The Byzantine Generals Problem – An Intro To Blockchain ...

Bitcoin Newcomers FAQ - Please read!

Welcome to the /Bitcoin Sticky FAQ

You've probably been hearing a lot about Bitcoin recently and are wondering what's the big deal? Most of your questions should be answered by the resources below but if you have additional questions feel free to ask them in the comments.
It all started with the release of the release of Satoshi Nakamoto's whitepaper however that will probably go over the head of most readers so we recommend the following videos for a good starting point for understanding how bitcoin works and a little about its long term potential:
Some other great resources include Lopp.net, the Princeton crypto series and James D'Angelo's Bitcoin 101 Blackboard series.
Some excellent writing on Bitcoin's value proposition and future can be found at the Satoshi Nakamoto Institute.
Some Bitcoin statistics can be found here and here. Developer resources can be found here. Peer-reviewed research papers can be found here.
Potential upcoming protocol improvements and scaling resources here and here.
The number of times Bitcoin was declared dead by the media can be found here (LOL!)

Key properties of Bitcoin

Where can I buy bitcoins?

Bitcoin.org and BuyBitcoinWorldwide.com are helpful sites for beginners. You can buy or sell any amount of bitcoin (even just a few dollars worth) and there are several easy methods to purchase bitcoin with cash, credit card or bank transfer. Some of the more popular resources are below, also check out the bitcoinity exchange resources for a larger list of options for purchases.
Here is a listing of local ATMs. If you would like your paycheck automatically converted to bitcoin use Bitwage.
Note: Bitcoins are valued at whatever market price people are willing to pay for them in balancing act of supply vs demand. Unlike traditional markets, bitcoin markets operate 24 hours per day, 365 days per year. Preev is a useful site that that shows how much various denominations of bitcoin are worth in different currencies. Alternatively you can just Google "1 bitcoin in (your local currency)".

Securing your bitcoins

With bitcoin you can "Be your own bank" and personally secure your bitcoins OR you can use third party companies aka "Bitcoin banks" which will hold the bitcoins for you.
Note: For increased security, use Two Factor Authentication (2FA) everywhere it is offered, including email!
2FA requires a second confirmation code to access your account making it much harder for thieves to gain access. Google Authenticator and Authy are the two most popular 2FA services, download links are below. Make sure you create backups of your 2FA codes.
Google Auth Authy OTP Auth
Android Android N/A
iOS iOS iOS

Watch out for scams

As mentioned above, Bitcoin is decentralized, which by definition means there is no official website or Twitter handle or spokesperson or CEO. However, all money attracts thieves. This combination unfortunately results in scammers running official sounding names or pretending to be an authority on YouTube or social media. Many scammers throughout the years have claimed to be the inventor of Bitcoin. Websites like bitcoin(dot)com and the btc subreddit are active scams. Almost all altcoins (shitcoins) are marketed heavily with big promises but are really just designed to separate you from your bitcoin. So be careful: any resource, including all linked in this document, may in the future turn evil. Don't trust, verify. Also as they say in our community "Not your keys, not your coins".

Where can I spend bitcoins?

Check out spendabit or bitcoin directory for millions of merchant options. Also you can spend bitcoin anywhere visa is accepted with bitcoin debit cards such as the CashApp card. Some other useful site are listed below.
Store Product
Gyft Gift cards for hundreds of retailers including Amazon, Target, Walmart, Starbucks, Whole Foods, CVS, Lowes, Home Depot, iTunes, Best Buy, Sears, Kohls, eBay, GameStop, etc.
Spendabit, Overstock and The Bitcoin Directory Retail shopping with millions of results
ShakePay Generate one time use Visa cards in seconds
NewEgg and Dell For all your electronics needs
Bitwa.la, Coinbills, Piixpay, Bitbill.eu, Bylls, Coins.ph, Bitrefill, LivingRoomofSatoshi, Coinsfer, and more Bill payment
Menufy, Takeaway and Thuisbezorgd NL Takeout delivered to your door
Expedia, Cheapair, Destinia, Abitsky, SkyTours, the Travel category on Gyft and 9flats For when you need to get away
Cryptostorm, Mullvad, and PIA VPN services
Namecheap, Porkbun Domain name registration
Stampnik Discounted USPS Priority, Express, First-Class mail postage
Coinmap and AirBitz are helpful to find local businesses accepting bitcoins. A good resource for UK residents is at wheretospendbitcoins.co.uk.
There are also lots of charities which accept bitcoin donations.

Merchant Resources

There are several benefits to accepting bitcoin as a payment option if you are a merchant;
If you are interested in accepting bitcoin as a payment method, there are several options available;

Can I mine bitcoin?

Mining bitcoins can be a fun learning experience, but be aware that you will most likely operate at a loss. Newcomers are often advised to stay away from mining unless they are only interested in it as a hobby similar to folding at home. If you want to learn more about mining you can read more here. Still have mining questions? The crew at /BitcoinMining would be happy to help you out.
If you want to contribute to the bitcoin network by hosting the blockchain and propagating transactions you can run a full node using this setup guide. If you would prefer to keep it simple there are several good options. You can view the global node distribution here.

Earning bitcoins

Just like any other form of money, you can also earn bitcoins by being paid to do a job.
Site Description
WorkingForBitcoins, Bitwage, Cryptogrind, Coinality, Bitgigs, /Jobs4Bitcoins, BitforTip, Rein Project Freelancing
Lolli Earn bitcoin when you shop online!
OpenBazaar, Purse.io, Bitify, /Bitmarket, 21 Market Marketplaces
/GirlsGoneBitcoin NSFW Adult services
A-ads, Coinzilla.io Advertising
You can also earn bitcoins by participating as a market maker on JoinMarket by allowing users to perform CoinJoin transactions with your bitcoins for a small fee (requires you to already have some bitcoins.

Bitcoin-Related Projects

The following is a short list of ongoing projects that might be worth taking a look at if you are interested in current development in the bitcoin space.
Project Description
Lightning Network Second layer scaling
Blockstream, Rootstock and Drivechain Sidechains
Hivemind and Augur Prediction markets
Tierion and Factom Records & Titles on the blockchain
BitMarkets, DropZone, Beaver and Open Bazaar Decentralized markets
JoinMarket and Wasabi Wallet CoinJoin implementation
Coinffeine and Bisq Decentralized bitcoin exchanges
Keybase Identity & Reputation management
Abra Global P2P money transmitter network
Bitcore Open source Bitcoin javascript library

Bitcoin Units

One Bitcoin is quite large (hundreds of £/$/€) so people often deal in smaller units. The most common subunits are listed below:
Unit Symbol Value Info
bitcoin BTC 1 bitcoin one bitcoin is equal to 100 million satoshis
millibitcoin mBTC 1,000 per bitcoin used as default unit in recent Electrum wallet releases
bit bit 1,000,000 per bitcoin colloquial "slang" term for microbitcoin (μBTC)
satoshi sat 100,000,000 per bitcoin smallest unit in bitcoin, named after the inventor
For example, assuming an arbitrary exchange rate of $10000 for one Bitcoin, a $10 meal would equal:
For more information check out the Bitcoin units wiki.
Still have questions? Feel free to ask in the comments below or stick around for our weekly Mentor Monday thread. If you decide to post a question in /Bitcoin, please use the search bar to see if it has been answered before, and remember to follow the community rules outlined on the sidebar to receive a better response. The mods are busy helping manage our community so please do not message them unless you notice problems with the functionality of the subreddit.
Note: This is a community created FAQ. If you notice anything missing from the FAQ or that requires clarification you can edit it here and it will be included in the next revision pending approval.
Welcome to the Bitcoin community and the new decentralized economy!
submitted by BitcoinFan7 to Bitcoin [link] [comments]

RiB Newsletter #16 – Secure Enclaves à la Crab

For the last few months we’ve been following new zero-knowledge proof projects in Rust. This month, with Secret Network upgrading their mainnet with secret contracts, it seems like a good opportunity to explore Rust blockchains that are using a completely different privacy-preserving technology: secure enclaves.
Secure enclaves are processes whose environment is protected from inspection by other processes, even the kernel, by special hardware. This protection particularly involves the encryption of a process’s memory. Software that wants to compute in secret can put those computations inside a secure enclave and, if everything works as expected, neither a local user, nor the hosting provider, can snoop on the computations being performed. The most notable implementation of secure enclaves is Intel’s SGX (Secure Guard Extensions).
Secure enclaves are an attractive way to perform private computation primarily because they don’t impose any limitations on what can be computed — code that runs inside SGX is more-or-less just regular x86 code, just running inside a special environment. But depending on SGX for privacy does have some special risks: software that runs in an SGX enclave must be signed (if transitively) by Intel’s own cryptographic keys, which means that Intel must approve of any software running in SGX, that Intel can revoke permission to use SGX, and that there is a risk of the signing keys being compromised; and it’s not obvious that secure enclaves are actually secure, there have already been a number of attacks against SGX. Regardless, as of now, hardware enclaves provide security features that aren’t feasible any other way.
There are two prominent Rust blockchains relying on SGX:
Outside of the blockchain world there are some other Rust projects using SGX, the most notable being:
Whether it’s secure enclaves or zk-SNARKs, Rust blockchains are walking the bleeding edge of privacy tech.
In unrelated RiB news, we recently received two donations,
Thanks so much to our anonymous donors. We don’t often receive donations, so this was a nice surprise! We intend to put all monetary contributions to use funding events or new contributors, and we’ll let you know what we do with the funds when we spend them.

Project Spotlight

Each month we like to shine a light on a notable Rust blockchain project. This month that project is…
Aleo.
Aleo is a zero-knowledge blockchain, with its own zero-knowledge programming language, Leo.
We don’t have a lot to say about it, but we think it looks cool. We hope they blog more.

Interesting Things

News

Blog Posts

Papers

Projects


Read more: https://rustinblockchain.org/newsletters/2020-09-30-secure-enclaves-a-la-crab/
submitted by Aimeedeer to rust [link] [comments]

Round up of Cryptocurrency News #5 Week 03/08 - 09/08

Welcome again to another recap and the first full week of the new month after breaking the downward trend on the monthly!
 
Firstly, from last weeks uptrend we have seen the market consolidate at this level throughout the week with a steady upward climb at the start of the week to a balance out above $11.5k for Bitcoin towards the end. For the market we have a total increase of $17.5B over the week but a 1% decrease of btc dominance moving mainly toward Chainlink and other altcoins.
 
Closing the week we have had some altcoin action, Ethereum breaking $400 midweek but now staying back in a nice channel between $350-$410 since the start of August. But, Chainlink killing it after breaking $10 and currently sitting comfortably above $13!! Other altcoins that have reaped rewards and I'm keeping an eye on are:
I have picked these as i have noticed they are usually the first movers or the biggest gainers after the market goes red. Chasing those quick gains!
 
What about the news for this week?
 
DISCORD LINK: https://discord.gg/zxXXyuJ 🍕 Bring some virtual pizza to share 🍕
Come have a chat, stimulate a discussion, ask a question or share some knowledge. We are all friendly crypto enthusiasts up for a chat, supportive and want to help each other with knowledge and investments!
Big thanks to our Telegram and My Crypto HQ for the constant news updates! The Gravychain Collective: https://t.me/gravychain My Crypto HQ: https://t.me/My_Crypto_HQ
Links
Important/Notable/Highlights:
Special Mentions:
Other:
submitted by IOTAbesomewhere to Gravychain [link] [comments]

Why only POW allows for digital scarcity that can be verified without trust

There's only one chain with the most pow. that can be verified and you won't have to depend on a person telling you which chain is the true chain.
Now take for example, Nano. Imagine forking nano 1000 times, each fork calls its network Nano. No rule changes but different transaction history. Fast and free means each of the 1000 forks can spam to pretend activity.
How can a person in 50 years verify independently which of the 1000 is the true version of history? He doesn't want to trust a single person. He doesn't want to be given a reciept (checkpoints). He doesn't want to be told to trust the cashier. He wants to look at the cash register and the cashier's hand and see for himself the transaction history so he can record it himself and checks to see if it matches the cashier's history.

"I'll use the wallet I have now." Doesn't work for the person in 50 years as he must trust you as the central authority figure.
Check github? Doesn't work for the person in 50 years as that can be gamed and he must trust no malarkey.
"oh try and fork nano and see if you can sell it." Okay but to a third person who doesn't trust me or you, he can't verify without human trust.
How is the byzantine general's problem solved without pow? Explain it to me in terms of 12 generals trying to decide yes or no to attack the city. Explain how it doesn't require trust as to decide.
Bitcoin is basically have one long message, append only. The generals follow the longest. You can't trick one general without spending the time to recreate the entire book. It converges on one message, one version of history, as it punishes whoever is trying to rewrite by slowly making them poor. In the case of the general, it wastes his energy until he dies. He either recognizes he can't and continues the honest message or dies.
submitted by Buttoshi to CryptoCurrency [link] [comments]

Bitcoin (BTC)A Peer-to-Peer Electronic Cash System.

Bitcoin (BTC)A Peer-to-Peer Electronic Cash System.
  • Bitcoin (BTC) is a peer-to-peer cryptocurrency that aims to function as a means of exchange that is independent of any central authority. BTC can be transferred electronically in a secure, verifiable, and immutable way.
  • Launched in 2009, BTC is the first virtual currency to solve the double-spending issue by timestamping transactions before broadcasting them to all of the nodes in the Bitcoin network. The Bitcoin Protocol offered a solution to the Byzantine Generals’ Problem with a blockchain network structure, a notion first created by Stuart Haber and W. Scott Stornetta in 1991.
  • Bitcoin’s whitepaper was published pseudonymously in 2008 by an individual, or a group, with the pseudonym “Satoshi Nakamoto”, whose underlying identity has still not been verified.
  • The Bitcoin protocol uses an SHA-256d-based Proof-of-Work (PoW) algorithm to reach network consensus. Its network has a target block time of 10 minutes and a maximum supply of 21 million tokens, with a decaying token emission rate. To prevent fluctuation of the block time, the network’s block difficulty is re-adjusted through an algorithm based on the past 2016 block times.
  • With a block size limit capped at 1 megabyte, the Bitcoin Protocol has supported both the Lightning Network, a second-layer infrastructure for payment channels, and Segregated Witness, a soft-fork to increase the number of transactions on a block, as solutions to network scalability.

https://preview.redd.it/s2gmpmeze3151.png?width=256&format=png&auto=webp&s=9759910dd3c4a15b83f55b827d1899fb2fdd3de1

1. What is Bitcoin (BTC)?

  • Bitcoin is a peer-to-peer cryptocurrency that aims to function as a means of exchange and is independent of any central authority. Bitcoins are transferred electronically in a secure, verifiable, and immutable way.
  • Network validators, whom are often referred to as miners, participate in the SHA-256d-based Proof-of-Work consensus mechanism to determine the next global state of the blockchain.
  • The Bitcoin protocol has a target block time of 10 minutes, and a maximum supply of 21 million tokens. The only way new bitcoins can be produced is when a block producer generates a new valid block.
  • The protocol has a token emission rate that halves every 210,000 blocks, or approximately every 4 years.
  • Unlike public blockchain infrastructures supporting the development of decentralized applications (Ethereum), the Bitcoin protocol is primarily used only for payments, and has only very limited support for smart contract-like functionalities (Bitcoin “Script” is mostly used to create certain conditions before bitcoins are used to be spent).

2. Bitcoin’s core features

For a more beginner’s introduction to Bitcoin, please visit Binance Academy’s guide to Bitcoin.

Unspent Transaction Output (UTXO) model

A UTXO transaction works like cash payment between two parties: Alice gives money to Bob and receives change (i.e., unspent amount). In comparison, blockchains like Ethereum rely on the account model.
https://preview.redd.it/t1j6anf8f3151.png?width=1601&format=png&auto=webp&s=33bd141d8f2136a6f32739c8cdc7aae2e04cbc47

Nakamoto consensus

In the Bitcoin network, anyone can join the network and become a bookkeeping service provider i.e., a validator. All validators are allowed in the race to become the block producer for the next block, yet only the first to complete a computationally heavy task will win. This feature is called Proof of Work (PoW).
The probability of any single validator to finish the task first is equal to the percentage of the total network computation power, or hash power, the validator has. For instance, a validator with 5% of the total network computation power will have a 5% chance of completing the task first, and therefore becoming the next block producer.
Since anyone can join the race, competition is prone to increase. In the early days, Bitcoin mining was mostly done by personal computer CPUs.
As of today, Bitcoin validators, or miners, have opted for dedicated and more powerful devices such as machines based on Application-Specific Integrated Circuit (“ASIC”).
Proof of Work secures the network as block producers must have spent resources external to the network (i.e., money to pay electricity), and can provide proof to other participants that they did so.
With various miners competing for block rewards, it becomes difficult for one single malicious party to gain network majority (defined as more than 51% of the network’s hash power in the Nakamoto consensus mechanism). The ability to rearrange transactions via 51% attacks indicates another feature of the Nakamoto consensus: the finality of transactions is only probabilistic.
Once a block is produced, it is then propagated by the block producer to all other validators to check on the validity of all transactions in that block. The block producer will receive rewards in the network’s native currency (i.e., bitcoin) as all validators approve the block and update their ledgers.

The blockchain

Block production

The Bitcoin protocol utilizes the Merkle tree data structure in order to organize hashes of numerous individual transactions into each block. This concept is named after Ralph Merkle, who patented it in 1979.
With the use of a Merkle tree, though each block might contain thousands of transactions, it will have the ability to combine all of their hashes and condense them into one, allowing efficient and secure verification of this group of transactions. This single hash called is a Merkle root, which is stored in the Block Header of a block. The Block Header also stores other meta information of a block, such as a hash of the previous Block Header, which enables blocks to be associated in a chain-like structure (hence the name “blockchain”).
An illustration of block production in the Bitcoin Protocol is demonstrated below.

https://preview.redd.it/m6texxicf3151.png?width=1591&format=png&auto=webp&s=f4253304912ed8370948b9c524e08fef28f1c78d

Block time and mining difficulty

Block time is the period required to create the next block in a network. As mentioned above, the node who solves the computationally intensive task will be allowed to produce the next block. Therefore, block time is directly correlated to the amount of time it takes for a node to find a solution to the task. The Bitcoin protocol sets a target block time of 10 minutes, and attempts to achieve this by introducing a variable named mining difficulty.
Mining difficulty refers to how difficult it is for the node to solve the computationally intensive task. If the network sets a high difficulty for the task, while miners have low computational power, which is often referred to as “hashrate”, it would statistically take longer for the nodes to get an answer for the task. If the difficulty is low, but miners have rather strong computational power, statistically, some nodes will be able to solve the task quickly.
Therefore, the 10 minute target block time is achieved by constantly and automatically adjusting the mining difficulty according to how much computational power there is amongst the nodes. The average block time of the network is evaluated after a certain number of blocks, and if it is greater than the expected block time, the difficulty level will decrease; if it is less than the expected block time, the difficulty level will increase.

What are orphan blocks?

In a PoW blockchain network, if the block time is too low, it would increase the likelihood of nodes producingorphan blocks, for which they would receive no reward. Orphan blocks are produced by nodes who solved the task but did not broadcast their results to the whole network the quickest due to network latency.
It takes time for a message to travel through a network, and it is entirely possible for 2 nodes to complete the task and start to broadcast their results to the network at roughly the same time, while one’s messages are received by all other nodes earlier as the node has low latency.
Imagine there is a network latency of 1 minute and a target block time of 2 minutes. A node could solve the task in around 1 minute but his message would take 1 minute to reach the rest of the nodes that are still working on the solution. While his message travels through the network, all the work done by all other nodes during that 1 minute, even if these nodes also complete the task, would go to waste. In this case, 50% of the computational power contributed to the network is wasted.
The percentage of wasted computational power would proportionally decrease if the mining difficulty were higher, as it would statistically take longer for miners to complete the task. In other words, if the mining difficulty, and therefore targeted block time is low, miners with powerful and often centralized mining facilities would get a higher chance of becoming the block producer, while the participation of weaker miners would become in vain. This introduces possible centralization and weakens the overall security of the network.
However, given a limited amount of transactions that can be stored in a block, making the block time too longwould decrease the number of transactions the network can process per second, negatively affecting network scalability.

3. Bitcoin’s additional features

Segregated Witness (SegWit)

Segregated Witness, often abbreviated as SegWit, is a protocol upgrade proposal that went live in August 2017.
SegWit separates witness signatures from transaction-related data. Witness signatures in legacy Bitcoin blocks often take more than 50% of the block size. By removing witness signatures from the transaction block, this protocol upgrade effectively increases the number of transactions that can be stored in a single block, enabling the network to handle more transactions per second. As a result, SegWit increases the scalability of Nakamoto consensus-based blockchain networks like Bitcoin and Litecoin.
SegWit also makes transactions cheaper. Since transaction fees are derived from how much data is being processed by the block producer, the more transactions that can be stored in a 1MB block, the cheaper individual transactions become.
https://preview.redd.it/depya70mf3151.png?width=1601&format=png&auto=webp&s=a6499aa2131fbf347f8ffd812930b2f7d66be48e
The legacy Bitcoin block has a block size limit of 1 megabyte, and any change on the block size would require a network hard-fork. On August 1st 2017, the first hard-fork occurred, leading to the creation of Bitcoin Cash (“BCH”), which introduced an 8 megabyte block size limit.
Conversely, Segregated Witness was a soft-fork: it never changed the transaction block size limit of the network. Instead, it added an extended block with an upper limit of 3 megabytes, which contains solely witness signatures, to the 1 megabyte block that contains only transaction data. This new block type can be processed even by nodes that have not completed the SegWit protocol upgrade.
Furthermore, the separation of witness signatures from transaction data solves the malleability issue with the original Bitcoin protocol. Without Segregated Witness, these signatures could be altered before the block is validated by miners. Indeed, alterations can be done in such a way that if the system does a mathematical check, the signature would still be valid. However, since the values in the signature are changed, the two signatures would create vastly different hash values.
For instance, if a witness signature states “6,” it has a mathematical value of 6, and would create a hash value of 12345. However, if the witness signature were changed to “06”, it would maintain a mathematical value of 6 while creating a (faulty) hash value of 67890.
Since the mathematical values are the same, the altered signature remains a valid signature. This would create a bookkeeping issue, as transactions in Nakamoto consensus-based blockchain networks are documented with these hash values, or transaction IDs. Effectively, one can alter a transaction ID to a new one, and the new ID can still be valid.
This can create many issues, as illustrated in the below example:
  1. Alice sends Bob 1 BTC, and Bob sends Merchant Carol this 1 BTC for some goods.
  2. Bob sends Carols this 1 BTC, while the transaction from Alice to Bob is not yet validated. Carol sees this incoming transaction of 1 BTC to him, and immediately ships goods to B.
  3. At the moment, the transaction from Alice to Bob is still not confirmed by the network, and Bob can change the witness signature, therefore changing this transaction ID from 12345 to 67890.
  4. Now Carol will not receive his 1 BTC, as the network looks for transaction 12345 to ensure that Bob’s wallet balance is valid.
  5. As this particular transaction ID changed from 12345 to 67890, the transaction from Bob to Carol will fail, and Bob will get his goods while still holding his BTC.
With the Segregated Witness upgrade, such instances can not happen again. This is because the witness signatures are moved outside of the transaction block into an extended block, and altering the witness signature won’t affect the transaction ID.
Since the transaction malleability issue is fixed, Segregated Witness also enables the proper functioning of second-layer scalability solutions on the Bitcoin protocol, such as the Lightning Network.

Lightning Network

Lightning Network is a second-layer micropayment solution for scalability.
Specifically, Lightning Network aims to enable near-instant and low-cost payments between merchants and customers that wish to use bitcoins.
Lightning Network was conceptualized in a whitepaper by Joseph Poon and Thaddeus Dryja in 2015. Since then, it has been implemented by multiple companies. The most prominent of them include Blockstream, Lightning Labs, and ACINQ.
A list of curated resources relevant to Lightning Network can be found here.
In the Lightning Network, if a customer wishes to transact with a merchant, both of them need to open a payment channel, which operates off the Bitcoin blockchain (i.e., off-chain vs. on-chain). None of the transaction details from this payment channel are recorded on the blockchain, and only when the channel is closed will the end result of both party’s wallet balances be updated to the blockchain. The blockchain only serves as a settlement layer for Lightning transactions.
Since all transactions done via the payment channel are conducted independently of the Nakamoto consensus, both parties involved in transactions do not need to wait for network confirmation on transactions. Instead, transacting parties would pay transaction fees to Bitcoin miners only when they decide to close the channel.
https://preview.redd.it/cy56icarf3151.png?width=1601&format=png&auto=webp&s=b239a63c6a87ec6cc1b18ce2cbd0355f8831c3a8
One limitation to the Lightning Network is that it requires a person to be online to receive transactions attributing towards him. Another limitation in user experience could be that one needs to lock up some funds every time he wishes to open a payment channel, and is only able to use that fund within the channel.
However, this does not mean he needs to create new channels every time he wishes to transact with a different person on the Lightning Network. If Alice wants to send money to Carol, but they do not have a payment channel open, they can ask Bob, who has payment channels open to both Alice and Carol, to help make that transaction. Alice will be able to send funds to Bob, and Bob to Carol. Hence, the number of “payment hubs” (i.e., Bob in the previous example) correlates with both the convenience and the usability of the Lightning Network for real-world applications.

Schnorr Signature upgrade proposal

Elliptic Curve Digital Signature Algorithm (“ECDSA”) signatures are used to sign transactions on the Bitcoin blockchain.
https://preview.redd.it/hjeqe4l7g3151.png?width=1601&format=png&auto=webp&s=8014fb08fe62ac4d91645499bc0c7e1c04c5d7c4
However, many developers now advocate for replacing ECDSA with Schnorr Signature. Once Schnorr Signatures are implemented, multiple parties can collaborate in producing a signature that is valid for the sum of their public keys.
This would primarily be beneficial for network scalability. When multiple addresses were to conduct transactions to a single address, each transaction would require their own signature. With Schnorr Signature, all these signatures would be combined into one. As a result, the network would be able to store more transactions in a single block.
https://preview.redd.it/axg3wayag3151.png?width=1601&format=png&auto=webp&s=93d958fa6b0e623caa82ca71fe457b4daa88c71e
The reduced size in signatures implies a reduced cost on transaction fees. The group of senders can split the transaction fees for that one group signature, instead of paying for one personal signature individually.
Schnorr Signature also improves network privacy and token fungibility. A third-party observer will not be able to detect if a user is sending a multi-signature transaction, since the signature will be in the same format as a single-signature transaction.

4. Economics and supply distribution

The Bitcoin protocol utilizes the Nakamoto consensus, and nodes validate blocks via Proof-of-Work mining. The bitcoin token was not pre-mined, and has a maximum supply of 21 million. The initial reward for a block was 50 BTC per block. Block mining rewards halve every 210,000 blocks. Since the average time for block production on the blockchain is 10 minutes, it implies that the block reward halving events will approximately take place every 4 years.
As of May 12th 2020, the block mining rewards are 6.25 BTC per block. Transaction fees also represent a minor revenue stream for miners.
submitted by D-platform to u/D-platform [link] [comments]

How can Stellar be so fast?

How can Stellar be so fast?
If you’ve used our XLMwallet, you know that Stellar is exceptionally fast compared to Bitcoin and Ethereum. How is it possible? They are all blockchains, after all. Does the high speed mean that Stellar is centralized? Not at all — here’s why.
With XLMwallet you can send and receive lumens (XLM) in under 5 seconds. For comparison: with Bitcoin, one confirmation takes 10 minutes (1 block time), and many exchanges and dApps require more than 3 confirmations. So your recipient will need to wait for half an hour or more to get their money.
5 seconds vs 10 minutes — it’s a 120x difference! How can one blockchain network be 120 times faster than another?
Some people who are not familiar with Stellar think that it must be centralized to be so efficient. But the truth is very different!
SCP vs PoW
The key reason why Stellar has such a huge processing speed is that it uses a completely different consensus protocol.
As you probably know, Bitcoin employs Proof-of-Work, where miners have to waste lots of resources trying to find a solution (hash) for each block. Network members together agree that the found hash is correct, and whoever found it first gets a reward. This agreement is known as consensus.
PoW a good system in the sense that it’s difficult to attack. A thief or hacker would need to spend a gigantic sum of money to force the network to agree on something that is not true. But PoW is also hugely wasteful. Maybe you’ve heard that Bitcoin mining consumes as much energy as a small country — it’s true!
The Byzantine problem
Instead of PoW, Stellar uses something called Federated Byzantine Agreement (FBA). This consensus model answers the same question: how can we make the nodes in the network work for the common good? How can we prevent evil agents (nodes) from colluding with each other and deceiving others?
The word Byzantine refers to the so-called Byzantine Generals Problem. The generals are sieging an enemy city, each with his own division. They have to decide if they want to attack, and the only way to communicate is to send a messenger. Some of the generals are actually enemy spies, so they send conflicting messages. Other messages can get lost. The problem is, how do we find out what the real generals think?
Stellar solution
Stellar’s Federated Byzantine Agreement can solve the problem. This model was created in 2015 by a professor from Stanford University. It’s too complicated to describe it in detail here, but here are some facts:
- All the nodes are divided into quorums (groups). Within each quorum, each node trusts some other nodes, and these ‘circles of trust’ are called slices.
- Nodes reach an agreement within each quorum.
- Different quorums intersect, and that ensures general agreement across the network.
- Even if many nodes turn ‘evil’ or get turned off, the system still reaches an agreement.
The bottom line is that there’s a very complex system of interlocking ‘agreement groups’, voting and ballots. Still, it’s many times faster than PoW — and yet very hard to break or hack into. You can read more here.
Even if you don’t know anything about consensus protocols, don’t worry. You can still use XLMwallet and enjoy all of its advantages: fast crypto transfers, user-friendly web interface, support for all Stellar assets (lumens and tokens), transfers by email, account merging, and so on.
By the way, now is still a good time to buy some more XLM. It’s been growing steadily and gained more than 20% in just one week. But there’s still a huge potental for growth after the Bitcoin halving on May 18.
So better make up your mind now — you can buy XLM on any major exchange. To protect your investment, withdraw the lumens from the exchange and store them safely in XLMwallet — the fastest, lightest web wallet for Stellar.
https://xlmwallet.co/
Web site — https://xlmwallet.co/
Medium — https://medium.com/@XLMwalletCo
Teletype — https://teletype.in/@XLMwalletCo
Twitter — https://twitter.com/XLMwalletCo
Reddit — https://www.reddit.com/XLM_wallet/
submitted by Stellar__wallet to XLM_wallet [link] [comments]

/r/Bitcoin FAQ - Newcomers please read

Welcome to the /Bitcoin Sticky FAQ

You've probably been hearing a lot about Bitcoin recently and are wondering what's the big deal? Most of your questions should be answered by the resources below but if you have additional questions feel free to ask them in the comments.
The following videos are a good starting point for understanding how bitcoin works and a little about its long term potential:
For some more great introductory videos check out Andreas Antonopoulos's YouTube playlists, he is probably the best bitcoin educator out there today. Also have to give mention to James D'Angelo's Bitcoin 101 Blackboard series. Lots of additional video resources can be found at the videos wiki page or /BitcoinTV.
Key properties of bitcoin
Some excellent writing on Bitcoin's value proposition and future can be found here. Bitcoin statistics can be found here, here and here. Developer resources can be found here and here. Peer-reviewed research papers can be found here. The number of times Bitcoin was declared dead by the media can be found here. Scaling resources here, and of course the whitepaper that started it all.

Where can I buy bitcoins?

BuyBitcoinWorldwide.com and Howtobuybitcoin.io are helpful sites for beginners. You can buy or sell any amount of bitcoin and there are several easy methods to purchase bitcoin with cash, credit card or bank transfer. Some of the more popular resources are below, also, check out the bitcoinity exchange resources for a larger list of options for purchases.
Bank Transfer Credit / Debit card Cash
Coinbase Coinbase LocalBitcoins
Gemini Bitstamp LibertyX
GDAX Bitit Mycelium LocalTrader
Bitstamp Cex.io BitQuick
Kraken CoinMama WallofCoins
Xapo BitcoinOTC
Cex.io
itBit
Bitit
Bitsquare
Here is a listing of local ATMs. If you would like your paycheck automatically converted to bitcoin use Cashila or Bitwage.
Note: Bitcoins are valued at whatever market price people are willing to pay for them in balancing act of supply vs demand. Unlike traditional markets, bitcoin markets operate 24 hours per day, 365 days per year. Preev is a useful site that that shows how much various denominations of bitcoin are worth in different currencies. Alternatively you can just Google "1 bitcoin in (your local currency)".

Securing your bitcoins

With bitcoin you can "Be your own bank" and personally secure your bitcoins OR you can use third party companies aka "Bitcoin banks" which will hold the bitcoins for you.
Android iOs Desktop
Mycelium BreadWallet Electrum
CoPay AirBitz Armory
Another interesting use case for physical storage/transfer is the Opendime. Opendime is a small USB stick that allows you to spend Bitcoin by physically passing it along so it's anonymous and tangible like cash.
Note: For increased security, use Two Factor Authentication (2FA) everywhere it is offered, including email!
2FA requires a second confirmation code to access your account, usually from a text message or app, making it much harder for thieves to gain access. Google Authenticator and Authy are the two most popular 2FA services, download links are below. Make sure you create backups of your 2FA codes.
Google Auth Authy
Android Android
iOS iOS

Where can I spend bitcoins?

A more comprehensive list can be found at the Trade FAQ but some more commons ones are below.
Store Product
Gyft Gift cards for hundreds of retailers including Amazon, Target, Walmart, Starbucks, Whole Foods, CVS, Lowes, Home Depot, iTunes, Best Buy, Sears, Kohls, eBay, GameStop, etc.
Steam, HumbleBundle, Games Planet, itch.io, g2g and kinguin For when you need to get your game on
Microsoft Xbox games, phone apps and software
Spendabit, The Bitcoin Shop, Overstock, DuoSearch, The Bitcoin Directory and BazaarBay Retail shopping with millions of results
ShakePay Generate one time use Visa cards in seconds
NewEgg and Dell For all your electronics needs
Cashila, Bitwa.la, Coinbills, Piixpay, Bitbill.eu, Bylls, Coins.ph, Bitrefill, Pey.de, LivingRoomofSatoshi, Hyphen.to, Coinsfer, GetPaidinBitcoin, Coins.co.th, More #1, #2 Bill payment
Foodler, Menufy, Takeaway, Thuisbezorgd NL, Pizza For Coins Takeout delivered to your door!
Expedia, Cheapair, Lot, Destinia, BTCTrip, Abitsky, SkyTours, Fluege the Travel category on Gyft and 9flats For when you need to get away
BoltVM, BitHost VPS service
Cryptostorm, Mullvad, and PIA VPN services
Namecheap, Porkbun For new domain name registration
Stampnik and GetUSPS Discounted USPS Priority, Express, First-Class mail postage
Reddit Gold Premium membership which can be gifted to others
Coinmap, 99Bitcoins and AirBitz are helpful to find local businesses accepting bitcoins. A good resource for UK residents is at wheretospendbitcoins.co.uk.
There are also lots of charities which accept bitcoin donations, such as Wikipedia, Red Cross, Amnesty International, United Way, ACLU and the EFF. You can find a longer list here.

Merchant Resources

There are several benefits to accepting bitcoin as a payment option if you are a merchant;
If you are interested in accepting bitcoin as a payment method, there are several options available;

Can I mine bitcoin?

Mining bitcoins can be a fun learning experience, but be aware that you will most likely operate at a loss. Newcomers are often advised to stay away from mining unless they are only interested in it as a hobby similar to folding at home. If you want to learn more about mining you can read more here. Still have mining questions? The crew at /BitcoinMining would be happy to help you out.
If you want to contribute to the bitcoin network by hosting the blockchain and propagating transactions you can run a full node using this setup guide. Bitseed is an easy option for getting set up. You can view the global node distribution here.

Earning bitcoins

Just like any other form of money, you can also earn bitcoins by being paid to do a job.
Site Description
WorkingForBitcoins, Bitwage, XBTfreelancer, Cryptogrind, Bitlancerr, Coinality, Bitgigs, /Jobs4Bitcoins, Rein Project Freelancing
OpenBazaar, Purse.io, Bitify, /Bitmarket, 21 Market Marketplaces
Watchmybit, Streamium.io, OTika.tv, XOtika.tv NSFW, /GirlsGoneBitcoin NSFW Video Streaming
Bitasker, BitforTip, WillPayCoin Tasks
Supload.com, SatoshiBox, JoyStream, File Army File/Image Sharing
CoinAd, A-ads, Coinzilla.io Advertising
You can also earn bitcoins by participating as a market maker on JoinMarket by allowing users to perform CoinJoin transactions with your bitcoins for a small fee (requires you to already have some bitcoins)

Bitcoin Projects

The following is a short list of ongoing projects that might be worth taking a look at if you are interested in current development in the bitcoin space.
Project Description
Lightning Network, Amiko Pay, and Strawpay Payment channels for network scaling
Blockstream and Drivechain Sidechains
21, Inc. Open source library for the machine payable web
ShapeShift.io Trade between bitcoins and altcoins easily
Open Transactions, Counterparty, Omni, Open Assets, Symbiont and Chain Financial asset platforms
Hivemind and Augur Prediction markets
Mirror Smart contracts
Mediachain Decentralized media library
Tierion and Factom Records & Titles on the blockchain
BitMarkets, DropZone, Beaver and Open Bazaar Decentralized markets
Samourai and Dark Wallet - abandoned Privacy-enhancing wallets
JoinMarket CoinJoin implementation (Increase privacy and/or Earn interest on bitcoin holdings)
Coinffeine and Bitsquare Decentralized bitcoin exchanges
Keybase and Bitrated Identity & Reputation management
Bitmesh and Telehash Mesh networking
JoyStream BitTorrent client with paid seeding
MORPHiS Decentralized, encrypted internet
Storj and Sia Decentralized file storage
Streamium and Faradam Pay in real time for on-demand services
Abra Global P2P money transmitter network
bitSIM PIN secure hardware token between SIM & Phone
Identifi Decentralized address book w/ ratings system
Coinometrics Institutional-level Bitcoin Data & Research
Blocktrail and BitGo Multisig bitcoin API
Bitcore Open source Bitcoin javascript library
Insight Open source blockchain API
Leet Kill your friends and take their money ;)

Bitcoin Units

One Bitcoin is quite large (hundreds of £/$/€) so people often deal in smaller units. The most common subunits are listed below:
Unit Symbol Value Info
millibitcoin mBTC 1,000 per bitcoin SI unit for milli i.e. millilitre (mL) or millimetre (mm)
microbitcoin μBTC 1,000,000 per bitcoin SI unit for micro i.e microlitre (μL) or micrometre (μm)
bit bit 1,000,000 per bitcoin Colloquial "slang" term for microbitcoin
satoshi sat 100,000,000 per bitcoin Smallest unit in bitcoin, named after the inventor
For example, assuming an arbitrary exchange rate of $500 for one Bitcoin, a $10 meal would equal:
For more information check out the Bitcoin units wiki.
Still have questions? Feel free to ask in the comments below or stick around for our weekly Mentor Monday thread. If you decide to post a question in /Bitcoin, please use the search bar to see if it has been answered before, and remember to follow the community rules outlined on the sidebar to receive a better response. The mods are busy helping manage our community so please do not message them unless you notice problems with the functionality of the subreddit. A complete list of bitcoin related subreddits can be found here
Note: This is a community created FAQ. If you notice anything missing from the FAQ or that requires clarification you can edit it here and it will be included in the next revision pending approval.
Welcome to the Bitcoin community and the new decentralized economy!
submitted by BinaryResult to Bitcoin [link] [comments]

/r/Bitcoin FAQ - Newcomers please read

Welcome to the /Bitcoin Sticky FAQ

You've probably been hearing a lot about Bitcoin recently and are wondering what's the big deal? Most of your questions should be answered by the resources below but if you have additional questions feel free to ask them in the comments.
Some great introductions for new users are My first bitcoin, Bitcoin explained and ELI5 Bitcoin. Also, the following videos are a good starting point for understanding how bitcoin works and a little about its long term potential:
Also have to give mention to Lopp.net, the Princeton crypto series and James D'Angelo's Bitcoin 101 Blackboard series. Some excellent writing on Bitcoin's value proposition and future can be found at the Satoshi Nakamoto Institute. Bitcoin statistics can be found here, here and here. Developer resources can be found here, here and here. Peer-reviewed research papers can be found here. Potential upcoming protocol improvements here. Scaling resources here. The number of times Bitcoin was declared dead by the media can be found here (LOL!), and of course Satoshi Nakamoto's whitepaper that started it all! :)
Key properties of bitcoin

Where can I buy bitcoins?

Bitcoin.org, BuyBitcoinWorldwide.com and Howtobuybitcoin.io are helpful sites for beginners. You can buy or sell any amount of bitcoin and there are several easy methods to purchase bitcoin with cash, credit card or bank transfer. Some of the more popular resources are below, also, check out the bitcoinity exchange resources for a larger list of options for purchases.
Bank Transfer Credit / Debit card Cash
Gemini Bitstamp LocalBitcoins
Bitstamp Bitit Mycelium LocalTrader
BitFinex Cex.io LibertyX
Cex.io CoinMama WallofCoins
Xapo Spectrocoin BitcoinOTC
Kraken Luno BitQuick
itBit
HitBTC
Bitit
Bisq (decentralized)
Luno
Spectrocoin
Here is a listing of local ATMs. If you would like your paycheck automatically converted to bitcoin use Bitwage.
Note: Bitcoins are valued at whatever market price people are willing to pay for them in balancing act of supply vs demand. Unlike traditional markets, bitcoin markets operate 24 hours per day, 365 days per year. Preev is a useful site that that shows how much various denominations of bitcoin are worth in different currencies. Alternatively you can just Google "1 bitcoin in (your local currency)".

Securing your bitcoins

With bitcoin you can "Be your own bank" and personally secure your bitcoins OR you can use third party companies aka "Bitcoin banks" which will hold the bitcoins for you.
Android iOs Desktop
Samouari BreadWallet Electrum
Another interesting use case for physical storage/transfer is the Opendime. Opendime is a small USB stick that allows you to spend Bitcoin by physically passing it along so it's anonymous and tangible like cash.
Note: For increased security, use Two Factor Authentication (2FA) everywhere it is offered, including email!
2FA requires a second confirmation code to access your account, usually from a text message or app, making it much harder for thieves to gain access. Google Authenticator and Authy are the two most popular 2FA services, download links are below. Make sure you create backups of your 2FA codes.
Google Auth Authy
Android Android
iOS iOS

Where can I spend bitcoins?

Check out spendabit or bitcoin directory for some good options, some of the more commons ones are listed below.
Store Product
Gyft Gift cards for hundreds of retailers including Amazon, Target, Walmart, Starbucks, Whole Foods, CVS, Lowes, Home Depot, iTunes, Best Buy, Sears, Kohls, eBay, GameStop, etc.
Steam, HumbleBundle, Games Planet, itch.io, g2g and kinguin For when you need to get your game on
Microsoft Xbox games, phone apps and software
Spendabit, Overstock, The Bitcoin Directory and BazaarBay Retail shopping with millions of results
ShakePay Generate one time use Visa cards in seconds
NewEgg and Dell For all your electronics needs
Bitwa.la, Coinbills, Piixpay, Bitbill.eu, Bylls, Coins.ph, Bitrefill, LivingRoomofSatoshi, Hyphen.to, Coinsfer, More #1, #2 Bill payment
Menufy, Takeaway, Thuisbezorgd NL, Pizza For Coins Takeout delivered to your door!
Expedia, Cheapair, Lot, Destinia, BTCTrip, Abitsky, SkyTours, Fluege the Travel category on Gyft and 9flats For when you need to get away
BitHost VPS service
Cryptostorm, Mullvad, and PIA VPN services
Namecheap, Porkbun For new domain name registration
Stampnik Discounted USPS Priority, Express, First-Class mail postage
Reddit Gold Premium membership which can be gifted to others
Coinmap and AirBitz are helpful to find local businesses accepting bitcoins. A good resource for UK residents is at wheretospendbitcoins.co.uk.
There are also lots of charities which accept bitcoin donations, such as Wikipedia, United Way, ACLU and the EFF. You can find a longer list here.

Merchant Resources

There are several benefits to accepting bitcoin as a payment option if you are a merchant;
If you are interested in accepting bitcoin as a payment method, there are several options available;

Can I mine bitcoin?

Mining bitcoins can be a fun learning experience, but be aware that you will most likely operate at a loss. Newcomers are often advised to stay away from mining unless they are only interested in it as a hobby similar to folding at home. If you want to learn more about mining you can read more here. Still have mining questions? The crew at /BitcoinMining would be happy to help you out.
If you want to contribute to the bitcoin network by hosting the blockchain and propagating transactions you can run a full node using this setup guide. Bitseed is an easy option for getting set up. You can view the global node distribution here.

Earning bitcoins

Just like any other form of money, you can also earn bitcoins by being paid to do a job.
Site Description
WorkingForBitcoins, Bitwage, XBTfreelancer, Cryptogrind, Bitlancerr, Coinality, Bitgigs, /Jobs4Bitcoins, Rein Project Freelancing
OpenBazaar, Purse.io, Bitify, /Bitmarket, 21 Market Marketplaces
Streamium.io, XOtika.tv NSFW, /GirlsGoneBitcoin NSFW Video Streaming
Bitasker, BitforTip Tasks
Supload.com, SatoshiBox, JoyStream, File Army File/Image Sharing
CoinAd, A-ads, Coinzilla.io Advertising
You can also earn bitcoins by participating as a market maker on JoinMarket by allowing users to perform CoinJoin transactions with your bitcoins for a small fee (requires you to already have some bitcoins)

Bitcoin Projects

The following is a short list of ongoing projects that might be worth taking a look at if you are interested in current development in the bitcoin space.
Project Description
Lightning Network, Amiko Pay, and Strawpay Payment channels for network scaling
Blockstream, Rootstock and Drivechain Sidechains
21, Inc. Open source library for the machine payable web
ShapeShift.io Trade between bitcoins and altcoins easily
Open Transactions, Counterparty, Omni, Open Assets, Symbiont and Chain Financial asset platforms
Hivemind and Augur Prediction markets
Mediachain Decentralized media library
Tierion and Factom Records & Titles on the blockchain
BitMarkets, DropZone, Beaver and Open Bazaar Decentralized markets
Samourai and Dark Wallet - abandoned Privacy-enhancing wallets
JoinMarket CoinJoin implementation (Increase privacy and/or Earn interest on bitcoin holdings)
Coinffeine and Bisq Decentralized bitcoin exchanges
Keybase and Bitrated Identity & Reputation management
Telehash Mesh networking
JoyStream BitTorrent client with paid seeding
MORPHiS Decentralized, encrypted internet
Storj and Sia Decentralized file storage
Streamium Pay in real time for on-demand services
Abra Global P2P money transmitter network
bitSIM PIN secure hardware token between SIM & Phone
Identifi Decentralized address book w/ ratings system
BitGo Multisig bitcoin API
Bitcore Open source Bitcoin javascript library
Insight Open source blockchain API
Leet Kill your friends and take their money ;)

Bitcoin Units

One Bitcoin is quite large (hundreds of £/$/€) so people often deal in smaller units. The most common subunits are listed below:
Unit Symbol Value Info
millibitcoin mBTC 1,000 per bitcoin SI unit for milli i.e. millilitre (mL) or millimetre (mm)
microbitcoin μBTC 1,000,000 per bitcoin SI unit for micro i.e microlitre (μL) or micrometre (μm)
bit bit 1,000,000 per bitcoin Colloquial "slang" term for microbitcoin
satoshi sat 100,000,000 per bitcoin Smallest unit in bitcoin, named after the inventor
For example, assuming an arbitrary exchange rate of $10000 for one Bitcoin, a $10 meal would equal:
For more information check out the Bitcoin units wiki.
Still have questions? Feel free to ask in the comments below or stick around for our weekly Mentor Monday thread. If you decide to post a question in /Bitcoin, please use the search bar to see if it has been answered before, and remember to follow the community rules outlined on the sidebar to receive a better response. The mods are busy helping manage our community so please do not message them unless you notice problems with the functionality of the subreddit. A complete list of bitcoin related subreddits can be found here
Note: This is a community created FAQ. If you notice anything missing from the FAQ or that requires clarification you can edit it here and it will be included in the next revision pending approval.
Welcome to the Bitcoin community and the new decentralized economy!
submitted by BinaryResult to Bitcoin [link] [comments]

Staking — The New Way to Earn Crypto for Free

Staking — The New Way to Earn Crypto for Free

https://preview.redd.it/jpadsinyz3c41.png?width=616&format=png&auto=webp&s=c0dc410484430b863b0488727f92135f218edff2
Airdrops are so 2017, free money was fun while it lasted but now when someone says free money in crypto, the first thoughts are scams and ponzi schemes. But in 2020, there is a way to earn free money, in a legitimate, common practice, and logical manner — staking.
Staking is the core concept behind the Proof-of-Stake (PoS) consensus protocol that is quickly becoming an industry standard throughout blockchain projects. PoS allows blockchains to scale effectively without compromising on security and resource efficiency. Projects that incorporate staking include aelf, Dash, EOS, Cosmos, Cardano, Dfinity and many others.

https://preview.redd.it/luczupo004c41.png?width=616&format=png&auto=webp&s=2a2aba11c35c9962e42d1ea56b9e4f33532750ef

PoW — Why change

First, let’s look at some of the issues facing Proof-of-Work (PoW) consensus that led to the development of PoS.
  1. Excessive energy consumption — In 2017, many concerns were raised over the amount of electricity used by the bitcoin network (Largest PoW blockchain). Since then the energy consumption has increased by over 400%, to the point where 1 single transaction on this network has the same carbon footprint of 736,722 Visa transactions or consumes the same amount of electricity as over 20 U.S. households.
  2. Varying Electricity Costs — The profit of any miner on the network is tied to two costs, the initial startup cost to obtain the hardware and infrastructure, and more critically, the running cost of said equipment in relation to electricity usage. Electricity costs can vary from fractions of a cent per kWh to over 50 cents (USD) and in some cases it is free. When a user may only be earning $0.40 USD per hour then this will clearly rule out certain demographics based purely on electricity costs, reducing the potential for complete decentralization.
  3. Reduced decentralization — Due to the high cost of the mining equipment, those with large financial bases setup mining farms, either for others to rent out individual miners or entirely for personal gains. This results in large demographic hotspots on the network reducing the decentralized aspect to a point where it no longer accomplishes this aspect.
  4. Conflicted interests — The requirements of running miners on the network are purely based on having possession of the hardware, electricity and internet connection. There are no limits to the amount a miner can earn, nor do they need to hold any stake in the network, and thus there is very little incentive for them to vote on upgrades that may benefit the network but reduce their rewards.
I want to take this moment to mention a potential benefit to PoW that I have not seen anyone mention previously. It is a very loose argument so don’t take this to heart too strongly.
Consistent Fiat Injection — The majority of miners will be paying for their electricity in fiat currency. At a conservative rate of $0.1 USD per kWh, the network currently uses 73.12 TWh per year. This equates to an average daily cost of over $20 million USD. This means every day around $20 million of fiat currency is effectively being injected into the bitcoin network. Although this concept is somewhat flawed in the sense that the same amount of bitcoin will be released each day regardless of how much is spent on electricity, I’m looking at this from the eyes of the miners, they are reducing their fiat bags and increasing their bitcoin bags. This change of bags is the essence of this point which will inevitably encourage crypto spending. If the bitcoin bags were increased but fiat bags did not decrease, then there would be less incentive to spend the bitcoin, as would see in a staking ecosystem.

https://preview.redd.it/8dtqt6e204c41.png?width=631&format=png&auto=webp&s=065aedde87b55f0768968307e59e62a35eac949d

PoS Variations

Different approaches have been taken to tackle different issues the PoS protocol faces. Will Little has an excellent article explaining this and more in PoS, but let me take an excerpt from his piece to go through them:
  • Coin-age selection — Blockchains like Peercoin (the first PoS chain), start out with PoW to distribute the coins, use coin age to help prevent monopolization and 51% attacks (by setting a time range when the probability of being selected as a node is greatest), and implement checkpoints initially to prevent NoS problems.
  • Randomized block selection — Chains like NXT and Blackcoin also use checkpoints, but believe that coin-age discourages staking. After an initial distribution period (either via PoW or otherwise), these chains use algorithms to randomly select nodes that can create blocks.
  • Ethereum’s Casper protocol(s) — Being already widely distributed, Ethereum doesn’t have to worry about the initial distribution problem when/if it switches to PoS. Casper takes a more Byzantine Fault Tolerant (BFT) approach and will punish nodes by taking away (“slashing”) their stake if they do devious things. In addition, consensus is formed by a multi-round process where every randomly assigned node votes for a specific block during a round.
  • Delegated Proof-of-Stake (DPoS) — Invented by Dan Larimer and first used in Bitshares (and then in [aelf,] Steem, EOS, and many others), DPoS tackles potential PoS problems by having the community “elect” delegates that will run nodes to create and validate blocks. Bad behavior is then punished by the community simply out-voting the delegated nodes.
  • Delegated Byzantine Fault Tolerance (DBFT) — Similar to DPoS, the NEO community votes for (delegates) nodes, but instead of each node producing blocks and agreeing on consensus, only 2 out of 3 nodes need to agree on what goes in every block (acting more like bookkeepers than validators).
  • Tendermint — As a more sophisticated form of DBFT and a precursor to Casper, Jae Kwon introduced tendermint in 2014, which leverages dynamic validator sets, rotating leader elections, and voting power (i.e. weight) that is proportional to the self-funding and community allocation of tokens to a node (i.e. a “validator”).
  • Masternodes — First introduced by DASH, a masternode PoS system requires nodes to stake a minimum threshold of coins in order to qualify as a node. Often this comes with requirements to provide “service” to a network in the form of governance, special payment protocols, etc…
  • Proof of Importance (POI)NEM takes a slightly different approach by granting an “importance calculation” to masternodes staking at least 10,000 XEM. This POI system then rewards active nodes that act in a positive way over time to impact the community.
  • “Proof-of-X” — And finally, there is no lack of activity in the PoS world to come up with clever approaches and variants of staking (some are more elaborate than others). In addition to BFT protocols such as Honeybadger, Ouroboros, and Tezos, for further reading, also check out “Proof-of-”: Stake Anonymous, Storage, Stake Time, Stake Velocity, Activity, Burn, and Capacity.
https://preview.redd.it/n28a8n5404c41.png?width=604&format=png&auto=webp&s=0ea8827fd0458e768d4eb3a0a1fa88c984ba0a82

Earning Your Stake

In order to understand how one can earn money from these networks, I’ll break them down into 3 categories: Simple staking, Running nodes, and Voting.
Simple Staking - This is the simplest of the 3 methods and requires almost no action by the user. Certain networks will reward users by simply holding tokens in a specified wallet. These rewards are generally minimal but are the easiest way to earn.
Running a node - This method provides the greatest rewards but also requires the greatest action by the user and most likely will require ongoing maintenance. Generally speaking, networks will require nodes to stake a certain amount of tokens often amounting to thousands of dollars. In DPoS systems, these nodes must be voted in by other users on the network and must continue to provide confidence to their supporters. Some companies will setup nodes and allow users to participate by contributing to the minimum staking amount, with a similar concept to PoW mining pools.
Voting - This mechanism works hand in hand with running nodes in relation to DPoS networks. Users are encouraged to vote for their preferred nodes by staking tokens as votes. Each vote will unlock a small amount of rewards for each voter, the nodes are normally the ones to provide these rewards as a portion of their own reward for running a node.

Aelf’s DPoS system

The aelf consensus protocol utilizes a form of DPoS. There are two versions of nodes on the network, active nodes & backup nodes (official names yet to be announced). Active nodes run the network and produce the blocks, while the backup nodes complete minor tasks and are on standby should any active nodes go offline or act maliciously. These nodes are selected based upon their number of votes received. Initially the top 17 nodes will be selected as active nodes, while the next 100 will stand as the backup ones, each voting period each node may change position should they receive more or less votes than the previous period. In order to be considered as a node, one must stake a minimum amount of ELF tokens (yet to be announced).

https://preview.redd.it/47d3wqe604c41.png?width=618&format=png&auto=webp&s=062a6aa6186b826d400a0015d4c91fd1a4ed0b65
In order to participate as a voter, there is no minimum amount of tokens to be staked. When one stakes, their tokens will be locked for a designated amount of time, selected by the voter from the preset periods. If users pull their tokens out before this locked period has expired no rewards are received, but if they leave them locked for the entire time frame they will receive the set reward, and the tokens will be automatically rolled over into the next locked period. As a result, should a voter decide, once their votes are cast, they can continue to receive rewards without any further action needed.
Many projects have tackled with node rewards in order to make them fair, well incentivized but sustainable for everyone involved. Aelf has come up with a reward structure based on multiple variables with a basic income guaranteed for every node. Variables may include the number of re-elections, number of votes received, or other elements.
As the system matures, the number of active nodes will be increased, resulting in a more diverse and secure network.
Staking as a solution is a win-win-win for network creators, users and investors. It is a much more resource efficient and scalable protocol to secure blockchain networks while reducing the entry point for users to earn from the system.
submitted by Floris-Jan to aelfofficial [link] [comments]

/r/Bitcoin FAQ - Newcomers please read

Welcome to the /Bitcoin Sticky FAQ

You've probably been hearing a lot about Bitcoin recently and are wondering what's the big deal? Most of your questions should be answered by the resources below but if you have additional questions feel free to ask them in the comments.
The following videos are a good starting point for understanding how bitcoin works and a little about its long term potential:
For lots of additional video resources check out the videos wiki page or /BitcoinTV.
Key properties of bitcoin
Some excellent writing on Bitcoin's value proposition and future can be found here. Bitcoin statistics can be found here and here. Developer resources can be found here and here. Peer-reviewed research papers can be found here. The number of times Bitcoin was declared dead by the media can be found here. Scaling resources here, and of course the whitepaper that started it all.

Where can I buy bitcoins?

BuyBitcoinWorldwide.com is a very helpful site for beginners. You can buy or sell any amount of bitcoin and there are several easy methods to purchase bitcoin with cash, credit card or bank transfer. Some of the more popular resources are below, also, check out the bitcoinity exchange resources for a larger list of options for purchases.
Bank Transfer Credit / Debit card Cash
Coinbase Coinbase LocalBitcoins
Gemini Bitstamp LibertyX
GDAX Bitit Mycelium LocalTrader
Bitstamp Cex.io BitQuick
Kraken CoinMama WallofCoins
Xapo BitcoinOTC
Cex.io
itBit
Bitit
Bitsquare
Here is a listing of local ATMs. If you would like your paycheck automatically converted to bitcoin use Cashila or Bitwage.
Note: Bitcoins are valued at whatever market price people are willing to pay for them in balancing act of supply vs demand. Unlike traditional markets, bitcoin markets operate 24 hours per day, 365 days per year. Preev is a useful site that that shows how much various denominations of bitcoin are worth in different currencies. Alternatively you can just Google "1 bitcoin in (your local currency)".

Securing your bitcoins

With bitcoin you can "Be your own bank" and personally secure your bitcoins OR you can use third party companies aka "Bitcoin banks" which will hold the bitcoins for you.
Android iOs Desktop
Mycelium BreadWallet Electrum
CoPay AirBitz Armory
Note: For increased security, use Two Factor Authentication (2FA) everywhere it is offered, including email!
2FA requires a second confirmation code to access your account, usually from a text message or app, making it much harder for thieves to gain access. Google Authenticator and Authy are the two most popular 2FA services, download links are below. Make sure you create backups of your 2FA codes.
Google Auth Authy
Android Android
iOS iOS

Where can I spend bitcoins?

A more comprehensive list can be found at the Trade FAQ but some more commons ones are below.
Store Product
Gyft Gift cards for hundreds of retailers including Amazon, Target, Walmart, Starbucks, Whole Foods, CVS, Lowes, Home Depot, iTunes, Best Buy, Sears, Kohls, eBay, GameStop, etc.
Steam, HumbleBundle, GreenmanGaming, and Coinplay.io For when you need to get your game on
Microsoft Xbox games, phone apps and software
Spendabit, The Bitcoin Shop, Overstock, Rakuten, DuoSearch, The Bitcoin Directory and BazaarBay Retail shopping with millions of results
ShakePay Generate one time use Visa cards in seconds
NewEgg, TigerDirect and Dell For all your electronics needs
Cashila, Bitwa.la, Coinbills, Piixpay, Bitbill.eu, Bylls, Coins.ph, Bitrefill, Pey.de, LivingRoomofSatoshi, Hyphen.to, Coinsfer, GetPaidinBitcoin, Coins.co.th, More #1, #2 Bill payment
Foodler, Takeaway, Thuisbezorgd NL, Pizza For Coins Takeout delivered to your door!
Expedia, Cheapair, Lot, Destinia, BTCTrip, Abitsky, SkyTours, Fluege the Travel category on Gyft and 9flats For when you need to get away
BoltVM, BitHost VPS service
Cryptostorm, Mullvad, and PIA VPN services
Namecheap For new domain name registration
Stampnik and GetUSPS Discounted USPS Priority, Express, First-Class mail postage
Reddit Gold Premium membership which can be gifted to others
Coinmap, 99Bitcoins and AirBitz are helpful to find local businesses accepting bitcoins. A good resource for UK residents is at wheretospendbitcoins.co.uk.
There are also lots of charities which accept bitcoin donations, such as Wikipedia, Red Cross, Amnesty International, United Way, ACLU and the EFF. You can find a longer list here.

Merchant Resources

There are several benefits to accepting bitcoin as a payment option if you are a merchant;
If you are interested in accepting bitcoin as a payment method, there are several options available;

Can I mine bitcoin?

Mining bitcoins can be a fun learning experience, but be aware that you will most likely operate at a loss. Newcomers are often advised to stay away from mining unless they are only interested in it as a hobby similar to folding at home. If you want to learn more about mining you can read more here. Still have mining questions? The crew at /BitcoinMining would be happy to help you out.
If you want to contribute to the bitcoin network by hosting the blockchain and propagating transactions you can run a full node using this setup guide. Bitseed is an easy option for getting set up. You can view the global node distribution here.

Earning bitcoins

Just like any other form of money, you can also earn bitcoins by being paid to do a job.
Site Description
Bitwage, XBTfreelancer, Cryptogrind, Bitlancerr, Coinality, Bitgigs, /Jobs4Bitcoins, Rein Project Freelancing
OpenBazaar, Purse.io, Bitify, /Bitmarket, 21 Market Marketplaces
Watchmybit, Streamium.io, OTika.tv, XOtika.tv NSFW, /GirlsGoneBitcoin NSFW Video Streaming
Bitasker, BitforTip, WillPayCoin Tasks
Supload.com, SatoshiBox, JoyStream, File Army File/Image Sharing
CoinAd, A-ads, Coinzilla.io Advertising
You can also earn bitcoins by participating as a market maker on JoinMarket by allowing users to perform CoinJoin transactions with your bitcoins for a small fee (requires you to already have some bitcoins)

Bitcoin Projects

The following is a short list of ongoing projects that might be worth taking a look at if you are interested in current development in the bitcoin space.
Project Description
Lightning Network, Amiko Pay, and Strawpay Payment channels for network scaling
Blockstream and Drivechain Sidechains
21, Inc. Open source library for the machine payable web
ShapeShift.io Trade between bitcoins and altcoins easily
Open Transactions, Counterparty, Omni, Open Assets, Symbiont and Chain Financial asset platforms
Hivemind and Augur Prediction markets
Mirror Smart contracts
Mediachain Decentralized media library
Tierion and Factom Records & Titles on the blockchain
BitMarkets, DropZone, Beaver and Open Bazaar Decentralized markets
Samourai and Dark Wallet - abandoned Privacy-enhancing wallets
JoinMarket CoinJoin implementation (Increase privacy and/or Earn interest on bitcoin holdings)
Coinffeine and Bitsquare Decentralized bitcoin exchanges
Keybase and Bitrated Identity & Reputation management
Bitmesh and Telehash Mesh networking
JoyStream BitTorrent client with paid seeding
MORPHiS Decentralized, encrypted internet
Storj and Sia Decentralized file storage
Streamium and Faradam Pay in real time for on-demand services
Abra Global P2P money transmitter network
bitSIM PIN secure hardware token between SIM & Phone
Identifi Decentralized address book w/ ratings system
Coinometrics Institutional-level Bitcoin Data & Research
Blocktrail and BitGo Multisig bitcoin API
Bitcore Open source Bitcoin javascript library
Insight Open source blockchain API
Leet Kill your friends and take their money ;)

Bitcoin Units

One Bitcoin is quite large (hundreds of £/$/€) so people often deal in smaller units. The most common subunits are listed below:
Unit Symbol Value Info
millibitcoin mBTC 1,000 per bitcoin SI unit for milli i.e. millilitre (mL) or millimetre (mm)
microbitcoin μBTC 1,000,000 per bitcoin SI unit for micro i.e microlitre (μL) or micrometre (μm)
bit bit 1,000,000 per bitcoin Colloquial "slang" term for microbitcoin
satoshi sat 100,000,000 per bitcoin Smallest unit in bitcoin, named after the inventor
For example, assuming an arbitrary exchange rate of $500 for one Bitcoin, a $10 meal would equal:
For more information check out the Bitcoin units wiki.
Still have questions? Feel free to ask in the comments below or stick around for our weekly Mentor Monday thread. If you decide to post a question in /Bitcoin, please use the search bar to see if it has been answered before, and remember to follow the community rules outlined on the sidebar to receive a better response. The mods are busy helping manage our community so please do not message them unless you notice problems with the functionality of the subreddit. A complete list of bitcoin related subreddits can be found here
Note: This is a community created FAQ. If you notice anything missing from the FAQ or that requires clarification you can edit it here and it will be included in the next revision pending approval.
Welcome to the Bitcoin community and the new decentralized economy!
submitted by BinaryResult to Bitcoin [link] [comments]

Searching for the Unicorn Cryptocurrency

Searching for the Unicorn Cryptocurrency
For someone first starting out as a cryptocurrency investor, finding a trustworthy manual for screening a cryptocurrency’s merits is nonexistent as we are still in the early, Wild West days of the cryptocurrency market. One would need to become deeply familiar with the inner workings of blockchain to be able to perform the bare minimum due diligence.
One might believe, over time, that finding the perfect cryptocurrency may be nothing short of futile. If a cryptocurrency purports infinite scalability, then it is probably either lightweight with limited features or it is highly centralized among a limited number of nodes that perform consensus services especially Proof of Stake or Delegated Proof of Stake. Similarly, a cryptocurrency that purports comprehensive privacy may have technical obstacles to overcome if it aims to expand its applications such as in smart contracts. The bottom line is that it is extremely difficult for a cryptocurrency to have all important features jam-packed into itself.
The cryptocurrency space is stuck in the era of the “dial-up internet” in a manner of speaking. Currently blockchain can’t scale – not without certain tradeoffs – and it hasn’t fully resolved certain intractable issues such as user-unfriendly long addresses and how the blockchain size is forever increasing to name two.
In other words, we haven’t found the ultimate cryptocurrency. That is, we haven’t found the mystical unicorn cryptocurrency that ushers the era of decentralization while eschewing all the limitations of traditional blockchain systems.
“But wait – what about Ethereum once it implements sharding?”
“Wouldn’t IOTA be able to scale infinitely with smart contracts through its Qubic offering?”
“Isn’t Dash capable of having privacy, smart contracts, and instantaneous transactions?”
Those thoughts and comments may come from cryptocurrency investors who have done their research. It is natural for the informed investors to invest in projects that are believed to bring cutting edge technological transformation to blockchain. Sooner or later, the sinking realization will hit that any variation of the current blockchain technology will always likely have certain limitations.
Let us pretend that there indeed exists a unicorn cryptocurrency somewhere that may or may not be here yet. What would it look like, exactly? Let us set the 5 criteria of the unicorn cryptocurrency:
Unicorn Criteria
(1) Perfectly solves the blockchain trilemma:
o Infinite scalability
o Full security
o Full decentralization
(2) Zero or minimal transaction fee
(3) Full privacy
(4) Full smart contract capabilities
(5) Fair distribution and fair governance
For each of the above 5 criteria, there would not be any middle ground. For example, a cryptocurrency with just an in-protocol mixer would not be considered as having full privacy. As another example, an Initial Coin Offering (ICO) may possibly violate criterion (5) since with an ICO the distribution and governance are often heavily favored towards an oligarchy – this in turn would defy the spirit of decentralization that Bitcoin was found on.
There is no cryptocurrency currently that fits the above profile of the unicorn cryptocurrency. Let us examine an arbitrary list of highly hyped cryptocurrencies that meet the above list at least partially. The following list is by no means comprehensive but may be a sufficient sampling of various blockchain implementations:
Bitcoin (BTC)
Bitcoin is the very first and the best known cryptocurrency that started it all. While Bitcoin is generally considered extremely secure, it suffers from mining centralization to a degree. Bitcoin is not anonymous, lacks smart contracts, and most worrisomely, can only do about 7 transactions per seconds (TPS). Bitcoin is not the unicorn notwithstanding all the Bitcoin maximalists.
Ethereum (ETH)
Ethereum is widely considered the gold standard of smart contracts aside from its scalability problem. Sharding as part of Casper’s release is generally considered to be the solution to Ethereum’s scalability problem.
The goal of sharding is to split up validating responsibilities among various groups or shards. Ethereum’s sharding comes down to duplicating the existing blockchain architecture and sharing a token. This does not solve the core issue and simply kicks the can further down the road. After all, full nodes still need to exist one way or another.
Ethereum’s blockchain size problem is also an issue as will be explained more later in this article.
As a result, Ethereum is not the unicorn due to its incomplete approach to scalability and, to a degree, security.
Dash
Dash’s masternodes are widely considered to be centralized due to their high funding requirements, and there are accounts of a pre-mine in the beginning. Dash is not the unicorn due to its questionable decentralization.
Nano
Nano boasts rightfully for its instant, free transactions. But it lacks smart contracts and privacy, and it may be exposed to well orchestrated DDOS attacks. Therefore, it goes without saying that Nano is not the unicorn.
EOS
While EOS claims to execute millions of transactions per seconds, a quick glance reveals centralized parameters with 21 nodes and a questionable governance system. Therefore, EOS fails to achieve the unicorn status.
Monero (XMR)
One of the best known and respected privacy coins, Monero lacks smart contracts and may fall short of infinite scalability due to CryptoNote’s design. The unicorn rank is out of Monero’s reach.
IOTA
IOTA’s scalability is based on the number of transactions the network processes, and so its supposedly infinite scalability would fluctuate and is subject to the whims of the underlying transactions. While IOTA’s scalability approach is innovative and may work in the long term, it should be reminded that the unicorn cryptocurrency has no middle ground. The unicorn cryptocurrency would be expected to scale infinitely on a consistent basis from the beginning.
In addition, IOTA’s Masked Authenticated Messaging (MAM) feature does not bring privacy to the masses in a highly convenient manner. Consequently, the unicorn is not found with IOTA.

PascalCoin as a Candidate for the Unicorn Cryptocurrency
Please allow me to present a candidate for the cryptocurrency unicorn: PascalCoin.
According to the website, PascalCoin claims the following:
“PascalCoin is an instant, zero-fee, infinitely scalable, and decentralized cryptocurrency with advanced privacy and smart contract capabilities. Enabled by the SafeBox technology to become the world’s first blockchain independent of historical operations, PascalCoin possesses unlimited potential.”
The above summary is a mouthful to be sure, but let’s take a deep dive on how PascalCoin innovates with the SafeBox and more. Before we do this, I encourage you to first become acquainted with PascalCoin by watching the following video introduction:
https://www.youtube.com/watch?time_continue=4&v=F25UU-0W9Dk
The rest of this section will be split into 10 parts in order to illustrate most of the notable features of PascalCoin. Naturally, let’s start off with the SafeBox.
Part #1: The SafeBox
Unlike traditional UTXO-based cryptocurrencies in which the blockchain records the specifics of each transaction (address, sender address, amount of funds transferred, etc.), the blockchain in PascalCoin is only used to mutate the SafeBox. The SafeBox is a separate but equivalent cryptographic data structure that snapshots account balances. PascalCoin’s blockchain is comparable to a machine that feeds the most important data – namely, the state of an account – into the SafeBox. Any node can still independently compute and verify the cumulative Proof-of-Work required to construct the SafeBox.
The PascalCoin whitepaper elegantly highlights the unique historical independence that the SafeBox possesses:
“While there are approaches that cryptocurrencies could use such as pruning, warp-sync, "finality checkpoints", UTXO-snapshotting, etc, there is a fundamental difference with PascalCoin. Their new nodes can only prove they are on most-work-chain using the infinite history whereas in PascalCoin, new nodes can prove they are on the most-work chain without the infinite history.”
Some cryptocurrency old-timers might instinctively balk at the idea of full nodes eschewing the entire history for security, but such a reaction would showcase a lack of understanding on what the SafeBox really does.
A concrete example would go a long way to best illustrate what the SafeBox does. Let’s say I input the following operations in my calculator:
5 * 5 – 10 / 2 + 5
It does not take a genius to calculate the answer, 25. Now, the expression “5 \ 5 – 10 / 2 + 5”* would be forever imbued on a traditional blockchain’s history. But the SafeBox begs to differ. It says that the expression “5 \ 5 – 10 / 2 + 5”* should instead be simply “25” so as preserve simplicity, time, and space. In other words, the SafeBox simply preserves the account balance.
But some might still be unsatisfied and claim that if one cannot trace the series of operations (transactions) that lead to the final number (balance) of 25, the blockchain is inherently insecure.
Here are four important security aspects of the SafeBox that some people fail to realize:
(1) SafeBox Follows the Longest Chain of Proof-of-Work
The SafeBox mutates itself per 100 blocks. Each new SafeBox mutation must reference both to the previous SafeBox mutation and the preceding 100 blocks in order to be valid, and the resultant hash of the new mutated SafeBox must then be referenced by each of the new subsequent blocks, and the process repeats itself forever.
The fact that each new SafeBox mutation must reference to the previous SafeBox mutation is comparable to relying on the entire history. This is because the previous SafeBox mutation encapsulates the result of cumulative entire history except for the 100 blocks which is why each new SafeBox mutation requires both the previous SafeBox mutation and the preceding 100 blocks.
So in a sense, there is a single interconnected chain of inflows and outflows, supported by Byzantine Proof-of-Work consensus, instead of the entire history of transactions.
More concretely, the SafeBox follows the path of the longest chain of Proof-of-Work simply by design, and is thus cryptographically equivalent to the entire history even without tracing specific operations in the past. If the chain is rolled back with a 51% attack, only the attacker’s own account(s) in the SafeBox can be manipulated as is explained in the next part.
(2) A 51% Attack on PascalCoin Functions the Same as Others
A 51% attack on PascalCoin would work in a similar way as with other Proof-of-Work cryptocurrencies. An attacker cannot modify a transaction in the past without affecting the current SafeBox hash which is accepted by all honest nodes.
Someone might claim that if you roll back all the current blocks plus the 100 blocks prior to the SafeBox’s mutation, one could create a forged SafeBox with different balances for all accounts. This would be incorrect as one would be able to manipulate only his or her own account(s) in the SafeBox with a 51% attack – just as is the case with other UTXO cryptocurrencies. The SafeBox stores the balances of all accounts which are in turn irreversibly linked only to their respective owners’ private keys.
(3) One Could Preserve the Entire History of the PascalCoin Blockchain
No blockchain data in PascalCoin is ever deleted even in the presence of the SafeBox. Since the SafeBox is cryptographically equivalent to a full node with the entire history as explained above, PascalCoin full nodes are not expected to contain infinite history. But for whatever reason(s) one may have, one could still keep all the PascalCoin blockchain history as well along with the SafeBox as an option even though it would be redundant.
Without storing the entire history of the PascalCoin blockchain, you can still trace the specific operations of the 100 blocks prior to when the SafeBox absorbs and reflects the net result (a single balance for each account) from those 100 blocks. But if you’re interested in tracing operations over a longer period in the past – as redundant as that may be – you’d have the option to do so by storing the entire history of the PascalCoin blockchain.
(4) The SafeBox is Equivalent to the Entire Blockchain History
Some skeptics may ask this question: “What if the SafeBox is forever lost? How would you be able to verify your accounts?” Asking this question is tantamount to asking to what would happen to Bitcoin if all of its entire history was erased. The result would be chaos, of course, but the SafeBox is still in line with the general security model of a traditional blockchain with respect to black swans.
Now that we know the security of the SafeBox is not compromised, what are the implications of this new blockchain paradigm? A colorful illustration as follows still wouldn’t do justice to the subtle revolution that the SafeBox ushers. The automobiles we see on the street are the cookie-and-butter representation of traditional blockchain systems. The SafeBox, on the other hand, supercharges those traditional cars to become the Transformers from Michael Bay’s films.
The SafeBox is an entirely different blockchain architecture that is impressive in its simplicity and ingenuity. The SafeBox’s design is only the opening act for PascalCoin’s vast nuclear arsenal. If the above was all that PascalCoin offers, it still wouldn’t come close to achieving the unicorn status but luckily, we have just scratched the surface. Please keep on reading on if you want to learn how PascalCoin is going to shatter the cryptocurrency industry into pieces. Buckle down as this is going to be a long read as we explore further about the SafeBox’s implications.
Part #2: 0-Confirmation Transactions
To begin, 0-confirmation transactions are secure in PascalCoin thanks to the SafeBox.
The following paraphrases an explanation of PascalCoin’s 0-confirmations from the whitepaper:
“Since PascalCoin is not a UTXO-based currency but rather a State-based currency thanks to the SafeBox, the security guarantee of 0-confirmation transactions are much stronger than in UTXO-based currencies. For example, in Bitcoin if a merchant accepts a 0-confirmation transaction for a coffee, the buyer can simply roll that transaction back after receiving the coffee but before the transaction is confirmed in a block. The way the buyer does this is by re-spending those UTXOs to himself in a new transaction (with a higher fee) thus invalidating them for the merchant. In PascalCoin, this is virtually impossible since the buyer's transaction to the merchant is simply a delta-operation to debit/credit a quantity from/to accounts respectively. The buyer is unable to erase or pre-empt this two-sided, debit/credit-based transaction from the network’s pending pool until it either enters a block for confirmation or is discarded with respect to both sender and receiver ends. If the buyer tries to double-spend the coffee funds after receiving the coffee but before they clear, the double-spend transaction will not propagate the network since nodes cannot propagate a double-spending transaction thanks to the debit/credit nature of the transaction. A UTXO-based transaction is initially one-sided before confirmation and therefore is more exposed to one-sided malicious schemes of double spending.”
Phew, that explanation was technical but it had to be done. In summary, PascalCoin possesses the only secure 0-confirmation transactions in the cryptocurrency industry, and it goes without saying that this means PascalCoin is extremely fast. In fact, PascalCoin is capable of 72,000 TPS even prior to any additional extensive optimizations down the road. In other words, PascalCoin is as instant as it gets and gives Nano a run for its money.
Part #3: Zero Fee
Let’s circle back to our discussion of PascalCoin’s 0-confirmation capability. Here’s a little fun magical twist to PascalCoin’s 0-confirmation magic: 0-confirmation transactions are zero-fee. As in you don’t pay a single cent in fee for each 0-confirmation! There is just a tiny downside: if you create a second transaction in a 5-minute block window then you’d need to pay a minimal fee. Imagine using Nano but with a significantly stronger anti-DDOS protection for spam! But there shouldn’t be any complaint as this fee would amount to 0.0001 Pascal or $0.00002 based on the current price of a Pascal at the time of this writing.
So, how come the fee for blazingly fast transactions is nonexistent? This is where the magic of the SafeBox arises in three ways:
(1) PascalCoin possesses the secure 0-confirmation feature as discussed above that enables this speed.
(2) There is no fee bidding competition of transaction priority typical in UTXO cryptocurrencies since, once again, PascalCoin operates on secure 0-confirmations.
(3) There is no fee incentive needed to run full nodes on behalf of the network’s security beyond the consensus rewards.
Part #4: Blockchain Size
Let’s expand more on the third point above, using Ethereum as an example. Since Ethereum’s launch in 2015, its full blockchain size is currently around 2 TB, give or take, but let’s just say its blockchain size is 100 GB for now to avoid offending the Ethereum elitists who insist there are different types of full nodes that are lighter. Whoever runs Ethereum’s full nodes would expect storage fees on top of the typical consensus fees as it takes significant resources to shoulder Ethereum’s full blockchain size and in turn secure the network. What if I told you that PascalCoin’s full blockchain size will never exceed few GBs after thousands of years? That is just what the SafeBox enables PascalCoin to do so. It is estimated that by 2072, PascalCoin’s full nodes will only be 6 GB which is low enough not to warrant any fee incentives for hosting full nodes. Remember, the SafeBox is an ultra-light cryptographic data structure that is cryptographically equivalent to a blockchain with the entire transaction history. In other words, the SafeBox is a compact spreadsheet of all account balances that functions as PascalCoin’s full node!
Not only does the SafeBox’s infinitesimal memory size helps to reduce transaction fees by phasing out any storage fees, but it also paves the way for true decentralization. It would be trivial for every PascalCoin user to opt a full node in the form of a wallet. This is extreme decentralization at its finest since the majority of users of other cryptocurrencies ditch full nodes due to their burdensome sizes. It is naïve to believe that storage costs would reduce enough to the point where hosting full nodes are trivial. Take a look at the following chart outlining the trend of storage cost.

* https://www.backblaze.com/blog/hard-drive-cost-per-gigabyte/
As we can see, storage costs continue to decrease but the descent is slowing down as is the norm with technological improvements. In the meantime, blockchain sizes of other cryptocurrencies are increasing linearly or, in the case of smart contract engines like Ethereum, parabolically. Imagine a cryptocurrency smart contract engine like Ethereum garnering worldwide adoption; how do you think Ethereum’s size would look like in the far future based on the following chart?


https://i.redd.it/k57nimdjmo621.png

Ethereum’s future blockchain size is not looking pretty in terms of sustainable security. Sharding is not a fix for this issue since there still needs to be full nodes but that is a different topic for another time.
It is astonishing that the cryptocurrency community as a whole has passively accepted this forever-expanding-blockchain-size problem as an inescapable fate.
PascalCoin is the only cryptocurrency that has fully escaped the death vortex of forever expanding blockchain size. Its blockchain size wouldn’t exceed 10 GB even after many hundreds of years of worldwide adoption. Ethereum’s blockchain size after hundreds of years of worldwide adoption would make fine comedy.
Part #5: Simple, Short, and Ordinal Addresses
Remember how the SafeBox works by snapshotting all account balances? As it turns out, the account address system is almost as cool as the SafeBox itself.
Imagine yourself in this situation: on a very hot and sunny day, you’re wandering down the street across from your house and ran into a lemonade stand – the old-fashioned kind without any QR code or credit card terminal. The kid across you is selling a lemonade cup for 1 Pascal with a poster outlining the payment address as 5471-55. You flip out your phone and click “Send” with 1 Pascal to the address 5471-55; viola, exactly one second later you’re drinking your lemonade without paying a cent for the transaction fee!
The last thing one wants to do is to figure out how to copy/paste to, say, the following address 1BoatSLRHtKNngkdXEeobR76b53LETtpyT on the spot wouldn’t it? Gone are the obnoxiously long addresses that plague all cryptocurrencies. The days of those unreadable addresses will be long gone – it has to be if blockchain is to innovate itself for the general public. EOS has a similar feature for readable addresses but in a very limited manner in comparison, and nicknames attached to addresses in GUIs don’t count since blockchain-wide compatibility wouldn’t hold.
Not only does PascalCoin has the neat feature of having addresses (called PASAs) that amount to up to 6 or 7 digits, but PascalCoin can also incorporate in-protocol address naming as opposed to GUI address nicknames. Suppose I want to order something from Amazon using Pascal; I simply search the word “Amazon” then the corresponding account number shows up. Pretty neat, right?
The astute reader may gather that PascalCoin’s address system makes it necessary to commoditize addresses, and he/she would be correct. Some view this as a weakness; part #10 later in this segment addresses this incorrect perception.
Part #6: Privacy
As if the above wasn’t enough, here’s another secret that PascalCoin has: it is a full-blown privacy coin. It uses two separate foundations to achieve comprehensive anonymity: in-protocol mixer for transfer amounts and zn-SNARKs for private balances. The former has been implemented and the latter is on the roadmap. Both the 0-confirmation transaction and the negligible transaction fee would make PascalCoin the most scalable privacy coin of any other cryptocurrencies pending the zk-SNARKs implementation.
Part #7: Smart Contracts
Next, PascalCoin will take smart contracts to the next level with a layer-2 overlay consensus system that pioneers sidechains and other smart contract implementations.
In formal terms, this layer-2 architecture will facilitate the transfer of data between PASAs which in turn allows clean enveloping of layer-2 protocols inside layer-1 much in the same way that HTTP lives inside TCP.
To summarize:
· The layer-2 consensus method is separate from the layer-1 Proof-of-Work. This layer-2 consensus method is independent and flexible. A sidechain – based on a single encompassing PASA – could apply Proof-of-Stake (POS), Delegated Proof-of-Stake (DPOS), or Directed Acyclic Graph (DAG) as the consensus system of its choice.
· Such a layer-2 smart contract platform can be written in any languages.
· Layer-2 sidechains will also provide very strong anonymity since funds are all pooled and keys are not used to unlock them.
· This layer-2 architecture is ingenious in which the computation is separate from layer-2 consensus, in effect removing any bottleneck.
· Horizontal scaling exists in this paradigm as there is no interdependence between smart contracts and states are not managed by slow sidechains.
· Speed and scalability are fully independent of PascalCoin.
One would be able to run the entire global financial system on PascalCoin’s infinitely scalable smart contract platform and it would still scale infinitely. In fact, this layer-2 architecture would be exponentially faster than Ethereum even after its sharding is implemented.
All this is the main focus of PascalCoin’s upcoming version 5 in 2019. A whitepaper add-on for this major upgrade will be released in early 2019.
Part #8: RandomHash Algorithm
Surely there must be some tradeoffs to PascalCoin’s impressive capabilities, you might be asking yourself. One might bring up the fact that PascalCoin’s layer-1 is based on Proof-of-Work and is thus susceptible to mining centralization. This would be a fallacy as PascalCoin has pioneered the very first true ASIC, GPU, and dual-mining resistant algorithm known as RandomHash that obliterates anything that is not CPU based and gives all the power back to solo miners.
Here is the official description of RandomHash:
“RandomHash is a high-level cryptographic hash algorithm that combines other well-known hash primitives in a highly serial manner. The distinguishing feature is that calculations for a nonce are dependent on partial calculations of other nonces, selected at random. This allows a serial hasher (CPU) to re-use these partial calculations in subsequent mining saving 50% or more of the work-load. Parallel hashers (GPU) cannot benefit from this optimization since the optimal nonce-set cannot be pre-calculated as it is determined on-the-fly. As a result, parallel hashers (GPU) are required to perform the full workload for every nonce. Also, the algorithm results in 10x memory bloat for a parallel implementation. In addition to its serial nature, it is branch-heavy and recursive making in optimal for CPU-only mining.”
One might be understandably skeptical of any Proof-of-Work algorithm that solves ASIC and GPU centralization once for all because there have been countless proposals being thrown around for various algorithms since the dawn of Bitcoin. Is RandomHash truly the ASIC & GPU killer that it claims to be?
Herman Schoenfeld, the inventor behind RandomHash, described his algorithm in the following:
“RandomHash offers endless ASIC-design breaking surface due to its use of recursion, hash algo selection, memory hardness and random number generation.
For example, changing how round hash selection is made and/or random number generator algo and/or checksum algo and/or their sequencing will totally break an ASIC design. Conceptually if you can significantly change the structure of the output assembly whilst keeping the high-level algorithm as invariant as possible, the ASIC design will necessarily require proportional restructuring. This results from the fact that ASIC designs mirror the ASM of the algorithm rather than the algorithm itself.”
Polyminer1 (pseudonym), one of the members of the PascalCoin core team who developed RHMiner (official software for mining RandomHash), claimed as follows:
“The design of RandomHash is, to my experience, a genuine innovation. I’ve been 30 years in the field. I’ve rarely been surprised by anything. RandomHash was one of my rare surprises. It’s elegant, simple, and achieves resistance in all fronts.”
PascalCoin may have been the first party to achieve the race of what could possibly be described as the “God algorithm” for Proof-of-Work cryptocurrencies. Look no further than one of Monero’s core developers since 2015, Howard Chu. In September 2018, Howard declared that he has found a solution, called RandomJS, to permanently keep ASICs off the network without repetitive algorithm changes. This solution actually closely mirrors RandomHash’s algorithm. Discussing about his algorithm, Howard asserted that “RandomJS is coming at the problem from a direction that nobody else is.”
Link to Howard Chu’s article on RandomJS:
https://www.coindesk.com/one-musicians-creative-solution-to-drive-asics-off-monero
Yet when Herman was asked about Howard’s approach, he responded:
“Yes, looks like it may work although using Javascript was a bit much. They should’ve just used an assembly subset and generated random ASM programs. In a way, RandomHash does this with its repeated use of random mem-transforms during expansion phase.”
In the end, PascalCoin may have successfully implemented the most revolutionary Proof-of-Work algorithm, one that eclipses Howard’s burgeoning vision, to date that almost nobody knows about. To learn more about RandomHash, refer to the following resources:
RandomHash whitepaper:
https://www.pascalcoin.org/storage/whitepapers/RandomHash_Whitepaper.pdf
Technical proposal for RandomHash:
https://github.com/PascalCoin/PascalCoin/blob/mastePIP/PIP-0009.md
Someone might claim that PascalCoin still suffers from mining centralization after RandomHash, and this is somewhat misleading as will be explained in part #10.
Part #9: Fair Distribution and Governance
Not only does PascalCoin rest on superior technology, but it also has its roots in the correct philosophy of decentralized distribution and governance. There was no ICO or pre-mine, and the developer fund exists as a percentage of mining rewards as voted by the community. This developer fund is 100% governed by a decentralized autonomous organization – currently facilitated by the PascalCoin Foundation – that will eventually be transformed into an autonomous smart contract platform. Not only is the developer fund voted upon by the community, but PascalCoin’s development roadmap is also voted upon the community via the Protocol Improvement Proposals (PIPs).
This decentralized governance also serves an important benefit as a powerful deterrent to unseemly fork wars that befall many cryptocurrencies.
Part #10: Common Misconceptions of PascalCoin
“The branding is terrible”
PascalCoin is currently working very hard on its image and is preparing for several branding and marketing initiatives in the short term. For example, two of the core developers of the PascalCoin recently interviewed with the Fox Business Network. A YouTube replay of this interview will be heavily promoted.
Some people object to the name PascalCoin. First, it’s worth noting that PascalCoin is the name of the project while Pascal is the name of the underlying currency. Secondly, Google and YouTube received excessive criticisms back then in the beginning with their name choices. Look at where those companies are nowadays – surely a somewhat similar situation faces PascalCoin until the name’s familiarity percolates into the public.
“The wallet GUI is terrible”
As the team is run by a small yet extremely dedicated developers, multiple priorities can be challenging to juggle. The lack of funding through an ICO or a pre-mine also makes it challenging to accelerate development. The top priority of the core developers is to continue developing full-time on the groundbreaking technology that PascalCoin offers. In the meantime, an updated and user-friendly wallet GUI has been worked upon for some time and will be released in due time. Rome wasn’t built in one day.
“One would need to purchase a PASA in the first place”
This is a complicated topic since PASAs need to be commoditized by the SafeBox’s design, meaning that PASAs cannot be obtained at no charge to prevent systematic abuse. This raises two seemingly valid concerns:
· As a chicken and egg problem, how would one purchase a PASA using Pascal in the first place if one cannot obtain Pascal without a PASA?
· How would the price of PASAs stay low and affordable in the face of significant demand?
With regards to the chicken and egg problem, there are many ways – some finished and some unfinished – to obtain your first PASA as explained on the “Get Started” page on the PascalCoin website:
https://www.pascalcoin.org/get_started
More importantly, however, is the fact that there are few methods that can get your first PASA for free. The team will also release another method soon in which you could obtain your first PASA for free via a single SMS message. This would probably become by far the simplest and the easiest way to obtain your first PASA for free. There will be more new ways to easily obtain your first PASA for free down the road.
What about ensuring the PASA market at large remains inexpensive and affordable following your first (and probably free) PASA acquisition? This would be achieved in two ways:
· Decentralized governance of the PASA economics per the explanation in the FAQ section on the bottom of the PascalCoin website (https://www.pascalcoin.org/)
· Unlimited and free pseudo-PASAs based on layer-2 in the next version release.
“PascalCoin is still centralized after the release of RandomHash”
Did the implementation of RandomHash from version 4 live up to its promise?
The official goals of RandomHash were as follow:
(1) Implement a GPU & ASIC resistant hash algorithm
(2) Eliminate dual mining
The two goals above were achieved by every possible measure.
Yet a mining pool, Nanopool, was able to regain its hash majority after a significant but a temporary dip.
The official conclusion is that, from a probabilistic viewpoint, solo miners are more profitable than pool miners. However, pool mining is enticing for solo miners who 1) have limited hardware as it ensures a steady income instead of highly profitable but probabilistic income via solo mining, and 2) who prefer convenient software and/or GUI.
What is the next step, then? While the barrier of entry for solo miners has successfully been put down, additional work needs to be done. The PascalCoin team and the community are earnestly investigating additional steps to improve mining decentralization with respect to pool mining specifically to add on top of RandomHash’s successful elimination of GPU, ASIC, and dual-mining dominance.
It is likely that the PascalCoin community will promote the following two initiatives in the near future:
(1) Establish a community-driven, nonprofit mining pool with attractive incentives.
(2) Optimize RHMiner, PascalCoin’s official solo mining software, for performance upgrades.
A single pool dominance is likely short lived once more options emerge for individual CPU miners who want to avoid solo mining for whatever reason(s).
Let us use Bitcoin as an example. Bitcoin mining is dominated by ASICs and mining pools but no single pool is – at the time of this writing – even close on obtaining the hash majority. With CPU solo mining being a feasible option in conjunction with ASIC and GPU mining eradication with RandomHash, the future hash rate distribution of PascalCoin would be far more promising than Bitcoin’s hash rate distribution.
PascalCoin is the Unicorn Cryptocurrency
If you’ve read this far, let’s cut straight to the point: PascalCoin IS the unicorn cryptocurrency.
It is worth noting that PascalCoin is still a young cryptocurrency as it was launched at the end of 2016. This means that many features are still work in progress such as zn-SNARKs, smart contracts, and pool decentralization to name few. However, it appears that all of the unicorn criteria are within PascalCoin’s reach once PascalCoin’s technical roadmap is mostly completed.
Based on this expository on PascalCoin’s technology, there is every reason to believe that PascalCoin is the unicorn cryptocurrency. PascalCoin also solves two fundamental blockchain problems beyond the unicorn criteria that were previously considered unsolvable: blockchain size and simple address system. The SafeBox pushes PascalCoin to the forefront of cryptocurrency zeitgeist since it is a superior solution compared to UTXO, Directed Acyclic Graph (DAG), Block Lattice, Tangle, and any other blockchain innovations.


THE UNICORN

Author: Tyler Swob
submitted by Kosass to CryptoCurrency [link] [comments]

Bitcoin and cryptocurrency mining explained - YouTube Byzantine Fault Tolerance in Bitcoin Bitcoin Q&A: Offline transactions and fault tolerance Cryptocurrency, Blockchain, and the Byzantine Generals Problem (Vitalik Buterin)  AI Podcast Clips El Problema del General Bizantino y blockchain

And that’s the Byzantine Generals’ Problem. Byzantine Generals’ Problem and Bitcoin. The above dilemma isn’t necessarily limited to just two generals. In a distributed network such as that of Bitcoin’s, all participants and nodes are essentially of equally hierarchy. The foundation of Bitcoin's security is that it solves the Byzantine Generals Problem (or Two Generals Problem) in a practical way.The problem is the challenge of taking a safe decision while communicating with other parties over an insecure network. The Byzantine Generals Problem is a common challenge that decentralized computer systems must overcome. Let’s look at this analogy and how it relates to modern data security. The Byzantine Generals Problem Research Paper. In 1982, Leslie Lamport, Robert Shostak, and Marshall Pease released a research paper titled, “The Byzantine Generals ... The Byzantine Generals’ Problem (henceforth mentioned as BGP) is a classic problem faced by any distributed computer system network. We have already discussed that Bitcoin is a decentralized ... [ July 17, 2020 ] Twitter Hacker Is Mixing Bitcoin Loot Using a Wasabi Wallet, Elliptic Says Crypto News Search for: Home Basics Of Bitcoin The Byzantine Generals Problem – An Intro To Blockchain The Byzantine Generals Problem – An Intro To Blockchain. November 22, 2019 admin Basics ...

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Bitcoin and cryptocurrency mining explained - YouTube

The Byzantine Generals Problem and Blockchain Consensus Models ... Two Generals' Problem Explained ... 8:25. Bitcoin and Byzantine Generals Programmer explains - Duration: 23:39. Ivan on Tech ... Vitalik Buterin is co-creator of and author of the white paper that launched Ethereum and ether, which is a cryptocurrency that is currently the second-largest digital currency after bitcoin. Does this solve the Byzantine Generals' Problem? NOTE: OpenDimes utilize some additional security measures, especially regarding key generation, which paper wallets and other physical bitcoins do not. These questions are from the MOOC sessions 7.2, 8.2, and 9.2 covering the Byzantine Generals' Problem, which took place on February 26th 2017, September 15th 2017, and February 23rd 2018 respectively. The Byzantine Generals Problem and Blockchain Consensus Models A Deep Dive ... WARNING!! FIAT COLLAPSING EVEN FASTER!!! Leaked Data, BITCOIN Breaking Out - Programmer explains - Duration ...

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