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Questions tagged [algorithms]

Regarding the underlying algorithms related to Bitcoin protocol.

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1answer
568 views

Shabal256 code explanation

Can anyone please explain the code below with comments? What are pbegin & pend ? What is ( I believe it is data, where it comes from ?): (pbegin == pend ? pblank : static_cast<const void*>(...
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1answer
387 views

What is the algorithm behind multisignature address?

I know you can create a multisignature address with the command: bitcoind createmultisig 2 ["pubkey1", "pubkey2", "pubkey3"] As described here: https://gist.github.com/gavinandresen/3966071 This ...
7
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1answer
521 views

Is Quark as secure as SHA 256?

I'm trying to make certain I'm understanding the purpose behind the Quark algorithm. There are lots of devices that need secure algorithms but have severe power and processing constraints such as ...
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1answer
411 views

Two identical transactions and hashes in Block Hashing algorithm

As I was reading Bitcoin hashing algorithm, I see that a Block Header contains hashes in the form of fields like hashPrevBlock , hashMerkleRoot . I have following questions: 1) Are the transactions ...
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2answers
751 views

What is the most lightweight proof-of-work algorithm?

I know litecoin was created back in the day using Scrypt as to make it more lightweight but also harder to build ASIC hardware from - so everyday computers could mine. Are there other algorithms one ...
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2answers
205 views

Why can't we expire two year old transactions?

I understand any output in blockchain can be left un-redeemed forever. But If we expire all transactions that are more than two years old (specifically after some number of blocks), there are some ...
3
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1answer
425 views

ASIC resistant PoW mechanism that generates new hash functions. How does that work?

From Vitalik Buterin's post regarding "On Mining", he mentions: The second approach is somewhat different: create a mechanism for generating new hash functions, and make the space of functions ...
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2answers
153 views

Are there any stochastically dependent proof of work algorithms?

In bitcoin, the probability of discovering a block on the X-th hash is the same1 as it is on the Y-th hash. As such, the probability of discovery is stochastically independent. Are there proof of ...
3
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2answers
378 views

Blockchain for internet-of-things or is there any mining algorithm that can be utilized in low-computational power devices preserving security?

Recently IBM and Microsoft showed their interest (IBM post, Microsoft post) in utilization of blockchain for internet of things development. Let's assume that in close future the blockchain technique ...
10
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1answer
1k views

What are the benefits of Invertible Bloom Lookup Tables for Bitcoin?

Gavin Andresen announced a few days ago, that he started working on Invertible Bloom Lookup Tables. His repository's README refers to two papers, What's the difference?: efficient set reconciliation ...
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2answers
210 views

WeaveCoin - Extremely High-Speed AltCoin - Is this Possible? [closed]

I've written a proposal for an extremely extremely high-speed transaction verification algorithm: http://kenthagerman.blogspot.ca/2014/08/weavecoin-high-speed-crypto-currency.html Is this possible? ...
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1answer
1k views

GPU mining strategies (algorithm)

I am currently in the process of creating a fairly simple bitcoin miner for CPU and GPU (for demonstration purposes not for money earning). However I am having a little troubling understanding how ...
4
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1answer
975 views

Ripple Distributed Consensus Algorithm

What kind of a Consensus Algorithms does ripple use? Is that a leader or leaderless distributed consensus algorithm? Then what?
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1answer
496 views

what is the difference between eatch coins wallet address,what is the coin public id/salt?

i looked at the link: http://brainwallet.org/ witch generate offline wallets for all major coins, i noticed that the same Passphrase generate different [Private Key&Address] pairs for eatch coin ...
18
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3answers
1k views

Looking for nonces of even numbers

Each one of bitcoin and its derived crypto-currencies has a nonce value in the block, no matter what the algorithm is. Every miner tries to search for a luck nonce which can make the hash value ...
2
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0answers
658 views

Ws2tcpip.h and winsock2.h on Window QT Wallet

Been trying for the past few days but couldn't get it working, I already download the latest cryptopp library but its seems that maxcoin got some issue compiling If I qmake "USE_UPNP=-" maxcoin-qt....
6
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1answer
5k views

How is the target section of a block header calculated?

I've been poking around https://en.bitcoin.it/wiki/Target and I've found the current target, but I can't seem to find how it's generated. It's supposedly generated when the difficulty is adjusted, as ...
5
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1answer
639 views

Does CPU mining become efficient as memory requirements increase?

I am focusing on an anti scrypt coin called Vertcoin which increases it's N-factor at a set interval. On their main page on bitcointalk it states that CPU computation will make gains as N-factor (...
2
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1answer
364 views

Why can addresses be shorter than 34 bytes?

The wiki entry on Address says: Some Bitcoin addresses can be shorter than 34 characters (as few as 27 in theory) and still be valid. [...] These shorter addresses are valid simply because they ...
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1answer
1k views

Bitcoin blockchain search algorithm and consistency policy

The blockchain looks like a double linked list, and all the transactions are stored into each block. What kind of algorithm does bitcoin use to find a specific transaction efficiently, since the ...
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3answers
988 views

Is difficult hashing algorithm necessary?

To avoid GPU/ASIC mining, difficult hashing functions, such as scrypt and scrypt-jane, are proposed as PoW algorithm (However, GPU and ASIC are also suitable for basic scrypt operation). Is it good ...
23
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1answer
13k views

How does the Kimoto Gravity Well regulate difficulty?

Maxcoin will use the Kimoto Gravity Well (KGW) to regulate the difficulty. From what I could find about the KGW, it retargets after every block and adjusts very quickly, e.g. when multipools add and ...
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4answers
7k views

Why can't we design a bitcoin that does useful work? [duplicate]

The bitcoin network, including every miner, is the biggest computing project that humanity has created. Thus I ask: why, instead of using it to generate useless data, don't we use it to generate ...
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1answer
517 views

What parameters are used to calculate the challenge string during bitcoin mining (blockchain creation)?

How is the challenge string computed mathematically? What's preventing some node on the bitcoin network from broadcasting a challenge + proof to other nodes as it's own when it received it from some ...
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1answer
214 views

Possible to temporarily reduce the supply of a cryptocurrency?

Does a cryptocurrency that can have its supply be reduced based on some factor currently exist? If not, is this possible? If so, how?
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2answers
617 views

Could an algorithm be made ASIC-resistant by simply adding deterministic permutations depending on the hash of the previous block and the nonce?

I was thinking of permuting bits in a block before it is hashed, in order to require some adaptability from the mining hardware while retaining the security of SHA-256. Permutations would depend on ...
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1answer
75 views

Question about mining algo [duplicate]

Lets say mining block is generated in 18:00, next block is generated after 10 minutes in 18:10 by user GENERATOR_18_10 As I understand, all transaction fees (for transactions included in 18:10) will ...
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2answers
6k views

Creating a bitcoin/litecoin miner with Javascript

I am a web developer and looking for well written technical documents about how bitcoin/litecoin works, what is the workflow, what is the algorithm and how can I write a miner from scratch by using ...
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2answers
4k views

How to sign a message using Bitcoin private key?

How does one create a proper signature for a given message using Bitcoin private keys? I have an input address of 5JeWZ1z6sRcLTJXdQEDdB986E6XfLAkj9CgNE4EHzr5GmjrVFpf or ...
3
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1answer
1k views

What values are hashed in the SHA-256 algorithm, and what would be the next iteration until a possible header is found?

I've been doing a lot of reading on mining and software related to mining but I can't quite get my head wrapped around the specific nature of what is being hashed together. So far I feel like the ...
9
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1answer
2k views

What complexity class is Bitcoin's proof-of-work (hashcash) in?

To formulate this question precisely, I will define an idealized hypothetical "perfect" hash function H(n) which has nice scalability properties, and will formulate a problem PERFECT HASHCASH in terms ...
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4answers
72k views

The bitcoin mining algorithm from a programmer's viewpoint

This page: Blocks said mining is actually to solve a mathematical problem, but reading Block hashing algorithm doesn't give much help. I also tried reading bitcoind source code, but reading code takes ...
5
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1answer
471 views

bitcoins can use different algorithm, how and implications

I read that if sha-256 was compromised at some point in the future, or for any other reason, bitcoin could switch to a different algorithm can someone detail how exactly that would work, and what the ...
4
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2answers
2k views

What determines SHA256 performance on different types of hardware?

I know the answers to many questions on here briefly touch on this point, but I'd like to get a consolidated answer that really touches on the key differences between different types of hardware which ...
4
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4answers
674 views

What if I create a new address and I'm given one which clashes (already exists, it is being used by other user)

Addresses are like GUIDs, no? They are created randomly whenever you request the creation of a new address. But what if when creating one, it clashes with one already created? I know that the ...
1
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1answer
644 views

How are bitcoins put in to circulation? [duplicate]

I'm excited because I bought my first bitcoins today! (0.41 bitcoins at that!) I'm wondering how they are put in to circulation? From my understanding it seems that the algorithm generates x bitcoins ...
2
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1answer
734 views

Hash rate for litecoind is way below the one I get for bitcoind, is this normal?

I'm running bitcoind on an Ubuntu EC2 image in the Amazon cloud; on another identical image I'm running litecoind. I compiled both of these on the bitcoind instance. According to the getmininginfo ...
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2answers
435 views

Is it possible that the authors of Bitcoin have an alternative way of generating bitcoins?

Is it possible that the Bitcoin creator (or developers) have an algorithm that allows computers to generate coins easily, but intentionally published only the current difficult mining algorithms. And, ...
4
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1answer
3k views

Can Artificial Intelligence be used to mine BitCoins faster?

Can Artificial Intelligence be used to find more efficient mining algorithms? Is there only one algorithm that can be used to mine? EDIT: Asking about running the SHA(SHA(block header)) more ...
8
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3answers
591 views

Defense from Government Intervention

What's to stop a government, say the U.S. government, from saying "Hey, it's okay if you want to use Bitcoins, but you have to use at least version 0.6.3". And then a year later changing the law to "...
3
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1answer
477 views

Is there a guaranteed hash for every block? [duplicate]

Possible Duplicate: Nonce size - Will it always be big enough? My question may be misphrased, if so, I'll correct it if you let me know in the comments. My understanding of mining is that the ...
13
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2answers
39k views

Simple bitcoin mining algorithm

I'm trying to figure out how does simple Bitcoin mining algorithm works in plain simple c or c# or some pseudo language. I've found an example at http://pastebin.com/EXDsRbYH, but unfortunately It ...
7
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3answers
977 views

Bitcoin protocol / algorithm scalability

I have been looking into the Bitcoin protocol / algorithm a bit. I have the basics down, I think, but there are a lot of questions about how the whole thing is supposed to scale. For example, Each ...
8
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3answers
8k views

How to calculate a hash of a Tx?

How does one calculate the hash of a Tx? Which fields need to be double SHA hashed and in what order?
3
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1answer
407 views

FirstBits address shortening algorithm

Is the algorithm used by FirstBits to create their shortened addresses described anywhere, so that anyone wanting to automatically generate them could generate the same result as asking the website ...
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3answers
419 views

Is there any consensus over specific improvements Bitcoin needs?

There has been some criticism from cryptography experts about the current Bitcoin algorithm(s). Now that Bitcoin has been released to the wild and everyone has had time to study it, is there any ...
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8answers
3k views

Are there algorithms that could be used for mining that resist acceleration with ASICs?

In my related question about mining algorithms that balance CPU and GPU it came up that such an algorithm would tremendously increase the incentive for people to create mining botnets. The prospect of ...