What is SHA256D? - Quora

Has anyone done an analysis on the correlation between the increases in Bitcoin mining difficulty and the value of the top 5 Altcoin SHA256d clones?

My hunch is that over time more 'profit motive' based miners will fall off the Bitcoin mining wagon and dedicate their hashing power (and faith) to other altcoin crypto-currencies. Which in turn could increase the price per unit of those coins.
TL;DR It might not be a bad idea to have an investment in a basket of SHA256d altcoins, the ones that have a great community backing them.
submitted by coolcityboy to Bitcoin [link] [comments]

Pure PoW is DEAD

When I was 16, camping out in an airport waiting to board my first International flight to England I began chatting with a U.S. Airforce pilot who had camped up beside my group. Asking him what it was like to fly at mach speeds he replied in a very sober expression, “you have to be alert at all times. You see a mountain or some obstacle appear on the horizon, you better adjust now or you’re going to slam into it.” Maybe he was adding dramatic effect, I’ve never flown at mach speeds at low altitudes, but I never forgot it and the analogy it carries...especially so fitting for technology and progress.
This past week in cryptocurrency shined an important (and hopefully sobering) light on a “mountain” that appeared on our industries horizon...and has actually been visible to us for far too long already: Pure Proof of Work’s inevitable fate.
By pure, I mean consensus algorithms that use nothing but the original Bitcoin proof of work consensus model without updates or algorithm changes to address its weaknesses relative to the ever expanding technology used to hash it. This means Bitcoin, today’s Ethereum, Zcash, Ethereum Classic, and other coins that comprise most of the value in the top 100 cryptocurrencies. The original, unmodified form of basic PoW that most of these coins use is dead. This demise may not be fully appreciated today, but as sure as a mach-speed plane, unable to turn in time is doomed to collide with a mountain in its path, these blockchains must soon either accept their lack of security in today’s world or fork and upgrade to more effective solutions, some of which have been pioneered by smaller projects that don’t command as much hash power and therefore already had to face and address their need for extra security.
I believe it’s actually irresponsible to deny it and assume economics, hash power, market, sentiment or even self-preservation of network participants will be protection enough.
Because Bitcoin is the biggest (by market cap) of the pure PoW cryptocurrencies in existence today, I’ll establish my arguments using BTC, but the same goes for all pure PoW cryptos.
1 - Economics Bitcoin is often defended because it has the largest market cap of all cryptocurrencies and commands most of the capable hash worldwide that might be used to attack it. It is a “store of value” with proponents of this argument relying on few factors, limited supply combined with sentiment being one of the most prominent. They believe that this limited supply will inevitably drive the price up and, somehow, bitcoin will remain unequivocally secured and established.
Bitcoin has serious limitations in its adherence to the pure PoW model, and though the realities of competition has kept it free from major 51% attacks, I predict that it’s only a matter of time before it cannot command the majority of hash power that may be used to attack it. Lack of acceptance that consensus must use more than just PoW, even when checkpoints are an already accepted as necessary augmentation, leaves Bitcoin open to a catastrophic failure at some point in the future, which would affect the short term value of every cryptocurrency, even those that have addressed and solved the most glaring security challenges of a pure PoW model. Some projects have developed and are now using more advanced, more secure technology than pure PoW, and still remain fully decentralized. This is now an area where altcoins are leading, as they fill the security vacuum. With altcoins also having smart contracts and advanced currency capabilities and being potential stores of value as well, the landscape visible on the horizon in front of us looks quite different from the smooth sailing we have seen behind us with respect to projects relying on PoW and PoW alone. I’m not suggesting that Bitcoin should try to be everything that every other altcoin is becoming, but to rely on its single function as an argument of it’s security and sustainability while refraining from important technical advancements to secure its future, is foolish. The calculator is an important, valuable, and useful tool, yet people understood that it should be part of a more multifunction solution and now carry one around inside their smartphone.
The argument supporting Bitcoin’s status quo as a pure PoW blockchain and claiming it is perfect as is for whatever particular reason, is often combined with the following and includes an argument resting on self-preservation. In other words, why would anyone be nefarious and ruin their own wealth and store of value given the enormous hash power and cost it would take to attack Bitcoin? Bitcoin, then, relies on theoretical protection with idealistic boundaries.
2 - Hash Power and Hardware Capabilities This is sort of a 2 in 1 argument. Bitcoin is considered by many, the most secure blockchain in terms of pure hash power. In other words, more hash power is directed at Bitcoin than any other cryptocurrency and, there are limits to sha256d hashing speeds, economically and in hardware capabilities therefore it would be too expensive to attack Bitcoin and by the same token, make no sense to the attacker to do any wrong in this case (self preservation).
To assume technology, A: is limited to what we know now and B: will remain within these bounds for long, is just ignorant. What happens when sha256d can be hashed faster, when hardware innovations change the cost and capabilities involved? How do we know it isn’t possible now? What’s more, will Bitcoin always hold its position as the “special” coin due to its leading network hashpower that simply will never experience a world where there is enough available hash power from other sources to use for a 51% attack? The argument that Bitcoin will remain special is not an argument that its technology can protect it, especially with its roots as a project that grew from a figurative David with its sights set on the Goliath of the banking industry.
Look at the enormous hash power presently directed at Bitcoin and ask, what happens if that hash power is suddenly directed at another, less special coin, as part of a 51% attack? Is that other coin ready to defend in some way against that event? And how does this then impact Bitcoin? I would submit that at the end of the analysis, if the only thing protecting Bitcoin and its current technology from being doublespent to death is the fact that it is uniquely “special” because it is biggest, then as it unarguably becomes centralized among the largest Bitcoin participants and/or institutions, in an ironic way, refusal to improve technology could create exactly the systemic centralization that Satoshi was trying to prevent.
Even so, the idea that Bitcoin can always and forever remain the largest cryptocurrency and “special” as such, ignores historical realities that teach us differently. Remember “alta-vista”, the pre-Google winner of the search engine wars? Remember AOL? MySpace? The economics of bitcoin as people understand them today, the economics involved in mining pure PoW, the sentiment and value assigned to bitcoin and any coin now, can change as rapidly as Bitcoin emerged, even unexpectedly to the masses.
The ETC attack of only a few days ago just put the entire Cryptocurrency industry on notice. Any project without an active solution in place of immunity or at least a defense against a 51% hash attack is in trouble. I would argue that even though it will likely still take some time for market dynamics to enable an attacker to reasonably mount a 51% attack on the largest pure PoW cryptocurrency, Bitcoin, without new defense against such an attack, it is a question of when, not if.
The other day I identified a small handful of projects that have developed and are using defenses against 51% hash attacks, only one of which has a provable solution of hash attack immunity in place.
It’s important to note, any solution that can be seen as real progress over the Bitcoin protocol must be one that is decentralized. While some cryptocurrencies solve the 51% hash attack problem with a fully centralized approach, that truly misses the point of the original Bitcoin paper. Centralized databases are a different technology altogether, and implementing a centralized solution to a decentralized technology changes it entirely, in which case it’s more akin to just trying to brand your centralized database with the latest catch phrases to gain attention, support or funding.
Here’s a short list I identified of projects who have developed a defense or a complete solution to 51% hash attacks. To my knowledge, all of these solutions are now active on the respective project main networks, with the exception of Litecoin Cash, which is running on testnet at this time.:
As an industry, we need to face the fact that pure PoW is an incomplete solution to decentralized blockchain security in this age of cheap, fungible compute power. Pure PoW-only systems must evolve, and it’s time we look beyond to understand what are the best solutions that have evolved to address that fact. If you are part of a crypto project, no matter how large, you ignore the notice provided by the ETC attack at your own peril and the peril of your network participants.
My request is this… if you know of a project with a 51% hash attack solution, please provide some information below. If you totally disagree with the main point of this post, please provide a reasoned argument to prove me wrong or explain why pure PoW systems will remain viable indefinitely. As an industry, it’s time we see the blunt reality and apply innovation. Those who don’t will be reduced to interesting historical experiments.
submitted by ethadvisor to CryptoCurrency [link] [comments]

Pure PoW is DEAD

When I was 16, camping out in an airport waiting to board my first International flight to England I began chatting with a U.S. Airforce pilot who had camped up beside my group. Asking him what it was like to fly at mach speeds he replied in a very sober expression, “you have to be alert at all times. You see a mountain or some obstacle appear on the horizon, you better adjust now or you’re going to slam into it.” Maybe he was adding dramatic effect, I’ve never flown at mach speeds at low altitudes, but I never forgot it and the analogy it carries...especially so fitting for technology and progress.
This past week in cryptocurrency shined an important (and hopefully sobering) light on a “mountain” that appeared on our industries horizon...and has actually been visible to us for far too long already: Pure Proof of Work’s inevitable fate.
By pure, I mean consensus algorithms that use nothing but the original Bitcoin proof of work consensus model without updates or algorithm changes to address its weaknesses relative to the ever expanding technology used to hash it. This means Bitcoin, today’s Ethereum, Zcash, Ethereum Classic, and other coins that comprise most of the value in the top 100 cryptocurrencies. The original, unmodified form of basic PoW that most of these coins use is dead. This demise may not be fully appreciated today, but as sure as a mach-speed plane, unable to turn in time is doomed to collide with a mountain in its path, these blockchains must soon either accept their lack of security in today’s world or fork and upgrade to more effective solutions, some of which have been pioneered by smaller projects that don’t command as much hash power and therefore already had to face and address their need for extra security.
I believe it’s actually irresponsible to deny it and assume economics, hash power, market, sentiment or even self-preservation of network participants will be protection enough.
Because Bitcoin is the biggest (by market cap) of the pure PoW cryptocurrencies in existence today, I’ll establish my arguments using BTC, but the same goes for all pure PoW cryptos.
1 - Economics Bitcoin is often defended because it has the largest market cap of all cryptocurrencies and commands most of the capable hash worldwide that might be used to attack it. It is a “store of value” with proponents of this argument relying on few factors, limited supply combined with sentiment being one of the most prominent. They believe that this limited supply will inevitably drive the price up and, somehow, bitcoin will remain unequivocally secured and established.
Bitcoin has serious limitations in its adherence to the pure PoW model, and though the realities of competition has kept it free from major 51% attacks, I predict that it’s only a matter of time before it cannot command the majority of hash power that may be used to attack it. Lack of acceptance that consensus must use more than just PoW, even when checkpoints are an already accepted as necessary augmentation, leaves Bitcoin open to a catastrophic failure at some point in the future, which would affect the short term value of every cryptocurrency, even those that have addressed and solved the most glaring security challenges of a pure PoW model. Some projects have developed and are now using more advanced, more secure technology than pure PoW, and still remain fully decentralized. This is now an area where altcoins are leading, as they fill the security vacuum. With altcoins also having smart contracts and advanced currency capabilities and being potential stores of value as well, the landscape visible on the horizon in front of us looks quite different from the smooth sailing we have seen behind us with respect to projects relying on PoW and PoW alone. I’m not suggesting that Bitcoin should try to be everything that every other altcoin is becoming, but to rely on its single function as an argument of it’s security and sustainability while refraining from important technical advancements to secure its future, is foolish. The calculator is an important, valuable, and useful tool, yet people understood that it should be part of a more multifunction solution and now carry one around inside their smartphone.
The argument supporting Bitcoin’s status quo as a pure PoW blockchain and claiming it is perfect as is for whatever particular reason, is often combined with the following and includes an argument resting on self-preservation. In other words, why would anyone be nefarious and ruin their own wealth and store of value given the enormous hash power and cost it would take to attack Bitcoin? Bitcoin, then, relies on theoretical protection with idealistic boundaries.
2 - Hash Power and Hardware Capabilities This is sort of a 2 in 1 argument. Bitcoin is considered by many, the most secure blockchain in terms of pure hash power. In other words, more hash power is directed at Bitcoin than any other cryptocurrency and, there are limits to sha256d hashing speeds, economically and in hardware capabilities therefore it would be too expensive to attack Bitcoin and by the same token, make no sense to the attacker to do any wrong in this case (self preservation).
To assume technology, A: is limited to what we know now and B: will remain within these bounds for long, is just ignorant. What happens when sha256d can be hashed faster, when hardware innovations change the cost and capabilities involved? How do we know it isn’t possible now? What’s more, will Bitcoin always hold its position as the “special” coin due to its leading network hashpower that simply will never experience a world where there is enough available hash power from other sources to use for a 51% attack? The argument that Bitcoin will remain special is not an argument that its technology can protect it, especially with its roots as a project that grew from a figurative David with its sights set on the Goliath of the banking industry.
Look at the enormous hash power presently directed at Bitcoin and ask, what happens if that hash power is suddenly directed at another, less special coin, as part of a 51% attack? Is that other coin ready to defend in some way against that event? And how does this then impact Bitcoin? I would submit that at the end of the analysis, if the only thing protecting Bitcoin and its current technology from being doublespent to death is the fact that it is uniquely “special” because it is biggest, then as it unarguably becomes centralized among the largest Bitcoin participants and/or institutions, in an ironic way, refusal to improve technology could create exactly the systemic centralization that Satoshi was trying to prevent.
Even so, the idea that Bitcoin can always and forever remain the largest cryptocurrency and “special” as such, ignores historical realities that teach us differently. Remember “alta-vista”, the pre-Google winner of the search engine wars? Remember AOL? MySpace? The economics of bitcoin as people understand them today, the economics involved in mining pure PoW, the sentiment and value assigned to bitcoin and any coin now, can change as rapidly as Bitcoin emerged, even unexpectedly to the masses.
The ETC attack of only a few days ago just put the entire Cryptocurrency industry on notice. Any project without an active solution in place of immunity or at least a defense against a 51% hash attack is in trouble. I would argue that even though it will likely still take some time for market dynamics to enable an attacker to reasonably mount a 51% attack on the largest pure PoW cryptocurrency, Bitcoin, without new defense against such an attack, it is a question of when, not if.
The other day I identified a small handful of projects that have developed and are using defenses against 51% hash attacks, only one of which has a provable solution of hash attack immunity in place.
It’s important to note, any solution that can be seen as real progress over the Bitcoin protocol must be one that is decentralized. While some cryptocurrencies solve the 51% hash attack problem with a fully centralized approach, that truly misses the point of the original Bitcoin paper. Centralized databases are a different technology altogether, and implementing a centralized solution to a decentralized technology changes it entirely, in which case it’s more akin to just trying to brand your centralized database with the latest catch phrases to gain attention, support or funding.
Here’s a short list I identified of projects who have developed a defense or a complete solution to 51% hash attacks. To my knowledge, all of these solutions are now active on the respective project main networks, with the exception of Litecoin Cash, which is running on testnet at this time.:
As an industry, we need to face the fact that pure PoW is an incomplete solution to decentralized blockchain security in this age of cheap, fungible compute power. Pure PoW-only systems must evolve, and it’s time we look beyond to understand what are the best solutions that have evolved to address that fact. If you are part of a crypto project, no matter how large, you ignore the notice provided by the ETC attack at your own peril and the peril of your network participants.
My request is this… if you know of a project with a 51% hash attack solution, please provide some information below. If you totally disagree with the main point of this post, please provide a reasoned argument to prove me wrong or explain why pure PoW systems will remain viable indefinitely. As an industry, it’s time we see the blunt reality and apply innovation. Those who don’t will be reduced to interesting historical experiments.
submitted by ethadvisor to CryptoTechnology [link] [comments]

So you’ve got your miner working, busy hashing away … but what is it really doing?

Posted for eternity @ https://vertcoin.easymine.online/articles/mining
Your miner is repeatedly hashing (see below for detail about a hash) a block of data, looking for a resulting output that is lower than a predetermined target. Each time this calculation is performed, one of the fields in the input data is changed, and this results in a different output. The output is not able to be determined until the work is completed – otherwise why would we bother doing the work in the first place?
Each hash takes a block header (see more below, but basically this is a 80-byte block of data). It runs this through the hashing function, and what comes out is a 32-byte output. For each, we usually represent that output in hexadecimal format, so it looks something like:
5da4bcb997a90bec188542365365d8b913af3f1eb7deaf55038cfcd04f0b11a0 
(that’s 64 hexadecimal characters – each character represents 4-bits. 64 x 4 bits = 256bit = 32 bytes)
The maximum value for our hash is:
FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF 
And the lowest is:
0000000000000000000000000000000000000000000000000000000000000000 
The goal in Proof-of-Work systems is to look for a hash that is lower than a specific target, i.e. starts with a specific number of leading zeros. This target is what determines the difficulty.
As the output of the hash is indeterminate, we look to statistics and probability to estimate how much work (i.e. attempts at hashing) we need to complete to find a hash that is lower than a specific target. So, we can therefore assume that to find a hash that starts with a leading zero will take, on average, 16 hashes. To find one that will start with two leading zeros (00), we’re looking at 256 hashes. Four leading zeros (0000) will take 65,536 hashes. Eight leading zeros (00000000) takes 4,294,967,296 hashes. So on and so on, until we realize that it will take 2 ^ 256 (a number too big for me to show here) attempts at hitting our minimum hash value.
Remember – this number of hashes is just an estimate. Think of it like rolling a dice. A 16-sided dice. And then rolling it 64 times in a row. And hoping to strike a specific number of leading zeros. Sometimes it will take far less than the estimate, sometimes it will take far more. Over a long enough time period though (with our dice it may take many billions of years), the averages hold true.
Difficulty is a measure used in cryptocurrencies to simply show how much work is needed to find a specific block. A block of difficulty 1 must have a hash smaller than:
00000000FFFF0000000000000000000000000000000000000000000000000000 
A block of difficulty 1/256 (0.00390625) must have a hash lower than:
000000FFFF000000000000000000000000000000000000000000000000000000 
And a block of difficulty 256 must have a hash lower than:
0000000000FFFF00000000000000000000000000000000000000000000000000 
So the higher the difficulty, the lower the hash must be; therefore more work must be completed to find the block.
Take a recent Vertcoin block – block # 852545, difficulty 41878.60056944499. This required a hash lower than:
000000000001909c000000000000000000000000000000000000000000000000 
The achieve finding this, a single miner would need to have completed, on average 179,867,219,848,013 hashes (calculated by taking the number of hashes needed for a difficulty 1 block - 4,294,967,296 or 2 ^ 32 or 16 ^ 8 – and multiplied by the difficulty). Of course, our single miner may have found this sooner – or later – than predicted.
Cryptocurrencies alter the required difficulty on a regular basis (some like Vertcoin do it after every block, others like Bitcoin or Litecoin do it every 2016 blocks), to ensure the correct number of blocks are found per day. As the hash rate of miners increases, so does the difficulty to ensure this average time between blocks remains the same. Likewise, as hash rate decreases, the difficulty decreases.
With difficulties as high as the above example, solo-mining (mining by yourself, not in a pool) becomes a very difficult task. Assume our miner can produce 100 MH/s. Plugging in this into the numbers above, we can see it’s going to take him (on average) 1,798,673 seconds of hashing to find a hash lower than the target – that’s just short of 21 days. But, if his luck is down, it could easily take twice that long. Or, if he’s lucky, half that time.
So, assuming he hit’s the average, for his 21 days mining he has earned 25 VTC.
Lets take another look at the same miner, but this time he’s going to join a pool, where he is working with a stack of other miners looking for that elusive hash. Assume the pool he has joined does 50 GH/s – in that case he has 0.1 / 50 or 0.2% of the pool’s hash rate. So for any blocks the pool finds he should earn 0.2% of 25 VTC = 0.05 VTC. At 50 GH/s, the pool should expect to spend 3,597 seconds between finding blocks (2 ^ 32 * difficulty / hashrate). So about every hour, our miner can expect to earn 0.05 VTC. This works out to be about 1.2 VTC per day, and when we extrapolate over the estimated 21 days of solo mining above, we’re back to 25 VTC.
The beauty of pooled-mining over solo-mining is that the time between blocks, whilst they can vary, should be closer to the predicted / estimated times over a shorter time period. The same applies when comparing pools – pools with a smaller hash rate will experience a greater variance in time between blocks than a pool with a greater hash rate. But in the end, looking back over a longer period of time, earnings will be the same.
Hashes
A Hash is a cryptographic function that can take an arbitrary sized block of data and maps it to a fixed sized output. It is a one-way function – only knowing the input data can one calculate the output; the reverse action is impossible. Also, small changes to the input data usually result in significant changes to the output value.
For example, take the following string:
“the quick brown fox jumps over the lazy dog” 
If we perform a SHA256 hash of this, it results in:
05c6e08f1d9fdafa03147fcb8f82f124c76d2f70e3d989dc8aadb5e7d7450bec 
If we change a single character in the input string (in this case we will replace the ‘o’ in ‘over’ to a zero), the resulting hash becomes:
de492f861d6bb8438f65b2beb2e98ae96a8519f19c24042b171d02ff4dfecc82 
Blocks
A block is made up of a header, and at least one transaction. The first transaction in the block is called the Coinbase transaction – it is the transactions that creates new coins, and it specifies the addresses that those coins go to. The Coinbase transaction is always the first transaction in a block, and there can only be one. All other transactions included in a block are transactions that send coins from one wallet address to another.
The block header is an 80-byte block of data that is made up of the following information in this order:
  • Version – a 32-bit/4-byte integer
  • Previous Block’s SHA256d Hash – 32 bytes
  • Merkle Hash of the Transactions – 32 bytes
  • Timestamp - a 32-bit/4-byte integer the represents the time of the block in seconds past 1st January 1970 00:00 UTC
  • nBits - a 32-bit/4-byte integer that represents the maximum value of the hash of the block
  • Nonce - a 32-bit/4-byte integer
The Version of a block remains relatively static through a coin’s lifetime – most blocks will have the same version. Typically only used to introduce new features or enforce new rules – for instance Segwit adoption is enforced by encoding information into the Version field.
The Previous Blocks’ Hash is simple a doubled SHA256 hash of the last valid blocks header.
The Merkle Hash is a hash generated by chaining all of the transactions together in a hash tree – thus ensuring that once a transaction is included in a block, it cannot be changed. It becomes a permanent record in the blockchain.
Timestamp loosely represents the time the block was generated – it does not have to be exact, anywhere within an hour each way of the real time will be accepted.
nBits – this is the maximum hash that this block must have in order to be considered valid. Bitcoin encodes the maximum hash into a 4-byte value as this is more efficient and provides sufficient accuracy.
Nonce – a simple 4-byte integer value that is incremented by a miner in order to find a resulting hash that is lower than that specified by nBits.
submitted by nzsquirrell to VertcoinMining [link] [comments]

A writing style comparaison between CSW and Satoshi

I would like to post this comment and let anyone make his own mind on how likely it is that CSW and Satoshi are the same person:
https://www.reddit.com/btc/comments/9uoy92/comment/e962non
The full thread, for the lulz:
A note. Many like to treat me like Casandra. Well, here is your warning to ignore at your peril. We will win this fast, or we will win this slow, but, we will win this. Others would like this to be "nicer", I would prefer a lesson. I want to have people understand Bitcoin.
If it means we spend a year or more slowly bleeding every satoshi of value one by one from the ABC chain, we will. Without exception. If ABC stays on SHA256d and does not add replay protection, we will hound it.
Not until it is weak, not until it is unlisted on every miner and major and home level exchange globally, but until the last CPU running it anywhere globally burns out If this means chasing a lone dev with a CPU to burn that last vestige of hope, and you think I will not...
Then, you do not know me! But, you will learn. This is not vengeance. It is a lesson. And I intend to burn it into the hearts and souls of all the socialists in ABC so their great grand children do not forget it! Have a nice day
The thing that strikes me straight away is how much he sounds like Satoshi Nakamto /s :
I wish you wouldn’t keep talking about me as a mysterious shadowy figure, the press just turns that into a pirate currency angle. Maybe instead make it about the open source project and give more credit to your dev contributors; it helps motivate them.
submitted by Ant-n to btc [link] [comments]

Airdropping masternodes — fair distribution & healthy economy of MTNC

One such worthwile project is Masternodecoin (MTNC), of which the first airdrop took place at the turn of August and September. Masternodecoin is a cryptocurrency based on DASH with 2MB block size, 60 blocks confirmation, and Proof of Stake (PoW SHA256d algorithm was only used to premine coins). Those lucky ones who supported this project from the beginning and participated in the first airdrop, got the amount needed to set up a masternode for free, but anyone who owns at least 50,000 coins can run a masternode. Masternodecoin rewards “connectivity age” instead of “coin age” thus eliminating the abuse from exchanges and users that do not actively contribute to the network. By having a static reward system, the rewards for participation are proportional to the work of each active node. Currently there are about 90 masternodes and the number is constantly increasing. These MTNC nodes allow instant transfers between addresses in a decentralized way, so even if several of them stop working, transactions are still validated without any problems. Masternodecoin also allows you to send funds using the DarkSend feature, which is fully anonymous, mixing coin transaction. Mixing removes any traces that would allow to discover the address or IP of sender. Imagine that you can transfer any amount of money to other side of the world in seconds, completely anonymously! With DarkSend, this is possible.
MTNC on Coinmarketcap.com The total number of created coins is almost 104,000,000, with about half amount in circulation (locked in masternodes or on wallets and exchanges). MTNC is listed on two well-known crypto exchanges — Cryptopia and NovaExchange. Current price ranges between 1800–2200 satoshi per one MTNC, which allows to set up a masternode for about $ 10,000 (assuming present bitcoin price at around $ 10,000) and ROI may vary between 200%-300%. Considering the growing popularity of cryptocurrencies with masternodes for steady passive income, this is not an excessive price, especially since the MTNC has a lot of potential for growth thanks to the currency development plans we can see on the roadmap below.
Masternodecoin roadmap The roadmap looks very appealing, thanks to the interesting features that dev plans to implement — search engine with private search or peer-to-peer chat with all messages after read, are just some of them. In addition, a very good idea for the whole currency ecosystem are the regular burnings of coins. By the end of November next year, half of the total supply of coins will be destroyed (50,000,000 MTNC). Thanks to this, as well as six rounds of airdrops, the distribution of coins is very fair, and anyone who sets up their masternode now should be happy with the future profits and growth of the MTNC value. With a huge amount of new blockchain projects and hundreds or even thousands of cryptcurrencies, it’s really hard to find such a remarkable project like Masternodecoin, with engaged dav and quickly growing community. If you are interested in Masternodecoin, you are most welcome to join the third round of airdrop, which is happening right now on the Bitcointalk forum. You can also join the discussion on the slack channel. Some useful links:
submitted by wwzsocki to CryptoCurrencies [link] [comments]

Myriadcoin Bounties List - Donate, Claim, and Suggest!

These are the latest bounties available to the Myriadcoin community. I wanted to showcase them here so I can stick them at the top of this subreddit for a while. The real bounty page is here: http://birdonwheels5.no-ip.org/myriad-bounty/index.php
Please donate to ones that interest you. Feel free to claim any of them here (you'll need to provide progress updates to me). Also, this is the place where you can suggest new bounties!
Cheers everyone!
  • Title: Youtube Tipping Bot
  • Description: Create a Youtube Tipper Bot for Myriadcoin. You may need to utilize Google+ Accounts. (For reference, Coinye was able to create one here: https://plus.google.com0/110820315203668613125/about)
  • Bounty Size: 100,000 MYR
  • Donation Address: MKgAspTqp9C5i44hWReqBksTcmAkwJK5y7
  • Title: Twitter Tipping Bot
  • Description: Create a bot that allows Myriadcoin to be transferred through tweets.
  • Bounty Size: 10,078 MYR
  • Donation Address: MTk3oCFV3CXixtdjufWjNFzw8D2jMkQ9H8
  • Title: Myriadcoin Videos
  • Description: Videos that Explain Myriad to People
  • Bounty Size: 44,222 MYR
  • Donation Address: MUygvsZao4RJKg7vRsB6iZczeN4bZvBjCg
  • Title: Written Technical Analysis of Enhanced Myriad Blockchain Security
  • Description: Written Technical Analysis of Enhanced Myriad Blockchain Security including how difficult a 51% attack would be to perform on 5 concurrent algorithms
  • Bounty Size: 15,501 MYR
  • Donation Address: M9NqqewwNVMnipqC8KRkBa7yB3dNsMEafa
  • Title: Publish a positive Myriadcoin Article on Coindesk
  • Description: See title. Please include in the article all the good juicy stuff. Topic - Myriadcoin and all the good stuff, 5 algos, really built for commerce/currency due to short block times (average 30secs, wide distribution and large amount of coins in circulation, accepted by major exchanges and some of the payment processors such as Coinpayment), one of the MOST FAIREST in coin distribution as able to mine with ASIC's, GPU's, CPU's, all with equal chance/amount and no instamine but very long block halvings; very very, VERY active development as evidenced by the github (updated to latest bitcoin core .0.9.2.1, not even #2 litecoin is updated to that level) and also as shown by myriadcoinplatform.org projects. Hmmm, I'm sure I missed some other stuff
  • Bounty Size: 500,000 MYR
  • Donation Address: MLXoT8YxmqYQgqmTMTihVY1z5PU9ePKuZL
  • Title: P2Pool Username Mod for PolyMYR
  • Description: Modify birdonwheels5's P2Pools to support the following: Ability to query the database for a user's payout address so users can connect with their username. All shares that are found for master and merged coins must be inserted into a MySQL database (SQL command MUST be configurable). Ideally we'd want usernames stored in the sharechain or something like that so people can mine with usernames on all nodes Does "usernames stored in the sharechain" sound familiar? Perhaps you could complete the "DNS Sidechain" bounty, and have a huge head-start on this one.
  • Bounty Size: 19,000 MYR
  • Donation Address: MJTQVUk2gnrtf4HxHiR3wn5B3gve2yEWqh
  • Title: DNS Sidechain
  • Description: Create a sidechain that acts as a public directory. This public directory will link a chosen Myriadcoin address to a specific username of the user's choosing. Users must be able to perform this linking via a webpage or the wallet. Both are preferred. An example would look something like: MSJ8nCKxxWicU8DMyqusdFF8v5L6DDvcrx to birdonwheels5. I would now be able to send Myriadcoins directly to birdonwheels5 with the syntax: [email protected] Linking a Myriad address to an email account would NOT work, because the addresses are stored directly on the blockchain, meaning anyone would be able to view your email address. This could potentially lead to spammers datamining the blockchain, and emailing en mass to all the addresses on the sidechain.
  • Bounty Size: 100,000
  • Donation Address: MR2fdh7sEsWDmk88Td9fD3sbNap9a6LBCx
  • Title: Launch a Multi-Algo Merge Mining Coin
  • Description: Create a multi-algo coin like Myriadcoin except enable auxPoW on at least 2 of the algorithms. You may want to utilize the multi-vPoW concept (myriadplatform.org/multi-vpow/) to retain value of your coin!
  • Bounty Size: 51,569 MYR
  • Donation Address: MJAR9WXeo382L1BJqCvpA7qnQEjtW1auyY
  • Title: SHA256D Merged Mining for p2p
  • Description: I'm looking for someone to turn my SHA256D pool into a multicultural pool! (still not allowed to pee in the water!!). So what i'm saying, i want merged mining enabled! There is currently 125K available for the one who creates this for us. Need anything? Questions? contact me (meziti) on IRC.As a bonus: If this bounty is completed before 14th september I add 50K Before 30th September I add 25K
  • Bounty Size: 175,000 MYR
  • Donation Address: MVTgHAKjiMPdrGD65ThgBaEj9x5Ff31MKX
  • Title: Node.js Developer for Counterparty
  • Description: Need to connect Node.js to the backend of our Myriad Counterparty fork.
  • Bounty Size: 350,000 MYR
  • Donation Address: MJXGQ9JWsBB837jFkeqPcvkcFwYNw8dMqX
  • Title: New Vendor Bounty
  • Description: The goal of this bounty is to incentivize the recruitment of new vendors. Each claim on the bounty will pay 50% of raised funds. Until the first vendor claims this, half of the current amount shown to the right of this description will be paid out.
  • Bounty Size: 220,001 MYR
  • Donation Address: MUrt9XsAUCdTzce5K36tdp5wu4imA6Vr8r
  • Title: Myriadcoin Sports Betting Website
  • Description: Create a sports betting website that accepts Myriadcoin. Some examples of bitcoin sports betting websites are http://directbet.eu/ and http://betcoinsports.com/#
  • Bounty Size: 0 MYR
  • Donation Address: M9YSL4Q8iCqL4sxW3db9vW3ACosPM6A18Q
  • Title: Create a CoinLock.com site for Myriad
  • Description: "Coinlock is the content selling platform for the Bitcoin ecosystem." Create a site like this for Myriadcoin!
  • Bounty Size: 40,000 MYR
  • Donation Address: M8smZfKGyt7uxo4UME941Ciw5kvh68LSc3
submitted by neuroMode to myriadcoin [link] [comments]

How DECOR++ can eradicate selfish mining incentive by design | Sergio Demian Lerner | Aug 16 2015

Sergio Demian Lerner on Aug 16 2015:
In these shocking forking times, nothing more relaxing that to immerse
yourself in a pure technical reading about cryptocurrency design, letting
aside Bitcoin politics for a moment. This message is about cryptocurrencies
design in general, so you're free to skip my message if you think it will
never apply to Bitcoin.
[ full article copied from my blog:
https://bitslog.wordpress.com/2015/08/16/how-decor-can-eradicate-selfish-mining-incentive-by-design/
]
A year ago I proposed the DECOR protocol
<https://bitslog.wordpress.com/2014/05/02/deco>, a new rule for
cryptocurrencies to reduce significantly the amount of orphan blocks and
then allow block rate to be as high as one block every 5 seconds, and at
the same time it promised to address the problem of selfish mining
<http://hackingdistributed.com/2013/11/04/bitcoin-is-broken/>. After one
year, I’ve received very little feedback about it. Yet the selfish mining
<http://hackingdistributed.com/2013/11/04/bitcoin-is-broken/> problem has
been argued over and over against certain changes in Bitcoin, as if selfish
mining were something inevitable to all POW-based cryptocurrencies. But it
is not.
In a nutshell, DECOR is a protocol that permits miners to share the block
reward if both mine competing blocks. This is done by publishing block
header siblings (sometime called uncles) into child blocks, and modifying
the cryptocurrency protocol to pay some amount to the miners of uncles. If
all miners are honest, this strategy increases slightly the probability of
1-block reversals, but reduces considerably the probability of longer
reversals, as all miners choose the same parent. A few months after my
post, Ethereum <https://www.ethereum.org/>adopted a similar strategy of
paying a certain amount of ether to uncles, but the amount paid was created
out of thin ear, and at that time there could be any amount of uncles, so
basically it distorted the money supply function into a uncapped
inflationary one, if all miners decided to collude. After I reported this
issue, they restricted the number of uncles that can be included, but still
it leaves an incentive for all miners to collude to increase miner revenue.
DECOR does reward sharing, so the supply function cap is maintained. But it
does not solve the Selfish mining problem: miners withholding a block get
paid a full reward but the remaining miners are working (without knowing
it) for a half of the block reward. So my original strategy does not work
for rational (but not necessarily honest) miners. A few posts later I
presented DECOR+ <https://bitslog.wordpress.com/2014/05/07/decor-2/> to try
to address the problem of unbalanced rewards: what happens if there are two
competing blocks, but one has a 12.5 BTC reward, but the other has a 20 BTC
reward due to additional fees? But again, if miners are dishonest, the
proposed scheme does not solve the underlying problem, as miners can
artificially increase their fees to win the conflict resolving rule, at
least in all cryptocurrencies that do not burn transaction fees. How can we
fix it?
DECOR++
We’ll fix DECOR by doing three changes. The first is by paying full rewards
to all competing blocks, either the parent or the uncles. To prevent
increasing the money supply, first we set a maximum number of uncles U than
can be included over a period of N blocks. For example we can set U=100 and
N=1000 (a maximum orphan rate of 10%). Then we create rule to decrease the
money supply per time interval in case it previously was increased. So to
prevent miners colluding to increase the money supply in U/N, we either
decrease the subsidies of the following N blocks by the excess amount in
the previous period or we make N coincident with block difficulty re-target
interval and we consider uncles in the rate computation, so mining
afterward simply gets more difficult. If all miners collude to try to
increase their revenue by U/N, they will see their revenue decrease by the
same amount in the following re-target interval.
Miners could start switching between two cryptocurrencies to mine only
during the low difficulty interval and avoid the high difficulty interval.
But here are no competing valuable non-merged mined cryptocurrency using
SHA256D, so this is no problem for Bitcoin. Also the cryptocurrency left
without mining power would become insecure and its price will fall to near
zero. So increasing the immaturity lock time for coinbases to at least N
blocks destroys any miner earnings if all decide to switch all at once.
The second change is to choose the parent block in case of conflict based
on a deterministic random selection in case of deciding between several
chains with the same accumulated difficulty but different tip: we order the
competing tip blocks by their hash digest values, we hash the hashes and we
use the resulting hash digest as seed to a PRNG to choose an index in the
sorted list of the block to choose as parent.
The third change is to process the transactions of all competing blocks
(the actual block and its siblings) in case of a conflict. The transactions
on the parent block will be processed first as normal. The others will be
processed in the order they are referenced in following child blocks.
Conflicting transactions (double-spends) present in uncle blocks with
respect to the main block are skipped, while obviously internal conflicts
in the uncle blocks make them invalid, as usual. Now, as long as the
subsidy dominates the fees, miners have no incentive to withhold blocks.
Let’s analyze what can happen in the long term, when fees dominate the
block reward. In the future there may be two kinds of transactions: public
transactions and private transactions. Public transactions are the current
standard transactions: they pay a fee in the standard way and are broadcast
over the public network. Private transactions may appear if miners decide
to negotiate inclusion in blocks directly with web wallets or gateways:
private transactions will pay fees as an output to the miner’s public key.
Blocks with high rewards competing with blocks with low rewards due to
public transactions will be rare, since for the benefit of the miner most
transactions included in blocks should be present in all other miners
memory pools to accelerate propagation, so all miners are exposed to the
same reward pool. If it happens (by the mistake of a user) that a public
transaction pays an extremely high fee, the withholding incentive may
reappear. But in a far future, when subsidy disappears and miners receive
the payment mainly because of fees, they may adopt the more competitive
commercial strategy of rely mainly in private transactions (or maybe using Mike
Hearn’s assurance contracts
<https://en.bitcoin.it/wiki/Funding_network_security>). As fees from
private transactions are not shared between competing blocks, they won’t
affect selfish mining. I conclude that DECOR++ is currently incentive
compatible and it is highly probable that remains incentive compatible in
the future.
To summarize, DECOR++ main protocol properties are:
Best regards, Sergio.
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UnbreakableCoin (UNB) Price Alert, Chart & News on BitScreener.com BITCOIN Mining is DYING, Start MINING LITECOIN with Home Built LITECOIN MINING RIG What is a Bitcoin hash and SHA-256 - YouTube Bitcoin Basics: #15 Bitcoin Security, SHA256 & P2P 1of2 (48) What is UnbreakableCoin?

SHA-256 is a member of the SHA-2 cryptographic hash functions designed by the NSA. SHA stands for Secure Hash Algorithm. Cryptographic hash functions are mathematical operations run on digital data; by comparing the computed "hash" (the output from execution of the algorithm) to a known and expected hash value, a person can determine the data's integrity. Bitcoin uses: SHA256(SHA256(Block_Header)) but you have to be careful about byte-order. For example, this python code will calculate the hash of the block with the smallest hash as of June 2011, Block 125552. The header is built from the six fields described above, concatenated together as little-endian values in hex notation: >>> import hashlib >>> header_hex = ("01000000 ... I've been wondering about this for a while. It might even be impossible due to hash value of block being SHA256 value of SHA256 value of the block data, as far as I know (or is this only for Bitcoin SHA-256 produces a 256-bit (32-byte) hash value. Data. SHA-256 hash. Calculate SHA256 hash # What is SHA-256? The SHA (Secure Hash Algorithm) is one of a number of cryptographic hash functions. A cryptographic hash is like a signature for a data set. If you would like to compare two sets of raw data (source of the file, text or similar) it is always better to hash it and compare SHA256 values ... Let H(M) be the SHA-256 hash of message M, then SHA-256D is simply H(H(M)). In short, hash of a hash. --A2A

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UnbreakableCoin (UNB) Price Alert, Chart & News on BitScreener.com

Recently Bitcoin (BTC) had a market cap of $8.48 billion and Litecoin (LTC) was at $485 million. Litecoin is based upon the Scrypt hashing algorithm and Bitcoin is based on SHA256D. Miners are ... More detail: https://bitscreener.com/coins/unbreakablecoin UnbreakableCoin (UNB) is a power-of-Work (POW) SHA256d clone of Bitcoin. UNB is based on Satoshi o... why bitcoin has value why bitcoin is better than gold why bitcoin mining why buy bitcoin why use bitcoin will bitcoin fail is bitcoin mining worth it how to buy bitcoins buy bitcoins invest in ... This video explains the concept of hashing and SHA-256 for newbies. For more information visit http://99bitcoins.com/what-is-bitcoin-hash/ UnbreakableCoin *UNB (*Trade Symbol) is a Digital CryptoCurrency, just like Bitcoin. It's built on Bitcoin's Unbreakable Sha256d algorithm and was redesigned to be 2x Faster, and over 3x Bigger.

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