A 256-bit variant of Secure Hash Algorithm 2

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Are Bitcoin Block Hashes Predictable

to create the block chain, the Bitcoin network runs hashing algorithms for each block, is it mathematically possible to predict the hash value of say, the 100th block from the last block currently in ...
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What is the point of comparing sha256 of downloaded file with published on the same website code? [closed]

Some websites publish sha256 to check authenticity of downloaded file. I suppose this is to protect against man-in-the-middle attack - that my file was not altered during download. What prevents ...
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Can ASIC miners easily be used to guess brainwallet passphrases?

After reading the Bitcoin wiki page for brainwallets it seems to me that mining equipment can be used to brute force brainwallet passphrases. Is this correct? "...so hackers can collectively try ...
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Does Bitcoin's SHA256 proof make a 51% attack more likely?

Ethereum's description says that Bitcoin's mining algorithm requires only a simple SHA256 computation, which caused the creation of specialised ASICs, which centralizes mining in the hands of a few ...
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In a perfect world, should RIPE160 be used as the block ID or transaction ID?

Edit: In this question I'm looking at storage advantages, and network bandwidth savings. Given that the TxID and BlockID uses SHA256 to uniquely identify a transaction (and block) is there any ...
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Can the bitcoin network hashrate be used for a 51% attack on other coins?

Please correct me if I am wrong. The difficulty constantly changes according to the current hash rate. It changes to ensure that a block is mined every 10 minutes. If the hash rate was 1000 TH/s and ...
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Bitcoin Address generation

The bitcoin wiki says this: How to create Bitcoin Address 0 - Having a private ECDSA key 18E14A7B6A307F426A94F8114701E7C8E774E7F9A47E2C2035DB29A206321725 1 - Take the corresponding public key ...
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How is the solution hash in a block generated?

For example, in the Genesis block in Bitcoin, from which values was the solution hash "000000000019d6689c085ae165831e934ff763ae46a2a6c172b3f1b60a8ce26f" derived from? I understand that the nonce is ...
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How to work out my hardware's hashrate power

Using my existing hardware, I want to work out which altcoin is still profitable to mine. I have found this link: http://dustcoin.com/mining But don't know which values to enter into the boxes at ...
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Is bitcoin mining itself compromising the security of SHA256

Following good scientific practice I propose a Theory/Hypothesis and now ask you to test it. Initially this is a "thought" experiment but may progress to real testing depending on your thoughts. Back ...
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1answer
477 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 ...
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Why was the RIPEMD-160 hash algorithms chosen before SHA-1?

Bitcoin uses both SHA-256 and RIPEMD-160 hashes. Most often a double-round SHA-256 is used, but for address generating, RIPEMD-160 is used because it generates a shorter hash value. RIPEMD-160 has a ...
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Using ASIC to password cracking - mad concept?

All ASIC for Bitcoin do a double SHA256 hash on an arbitrary string. But maybe they might be used for pen testing :-) Lets assume we have single SHA256 hash we want to crack. We also have an ASIC ...
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If SHA256 were compromised tomorrow, would Bitcoin collapse, or is there some contingency plan to move the network to a new hashing algorithm?

Hashing algorithms have a long history of becoming widespread and then declared insecure - MD5 is a good example. As Bitcoin increases ever more in popularity, and cryptanalysis becomes ever more ...
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Why some getwork has no nonce (on avalon asic, but other asic may come up)

i am testing miner asic to implement my own getwork hasher IP, and i found some interesting results. getwork from the pool may generate no-nonce result and the asic chip keeps running until reaching ...
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230 views

SHA256 Implementation Gate Equivalent

I needed help in understanding how to calculate the GE for a SHA256 implementation. I need to calculate the GE of individual functions in the SHA256 hashing algorithm. Could anyone please direct me ...
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What is the fastest public SHA256^2 code for x86?

I am asking about the double SHA256 hashing function - the one that bitcoin uses. Which publicly available implementation is the fastest one out there? It can be in assembler, as long as it is for ...
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709 views

Solving a block and verification of transactions [duplicate]

My understanding of mining is that the reason an award of Bitcoin comes along with the solving of the current block is to give people incentive to actually try to solve the block. My understanding is ...
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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 ...
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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 ...
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1answer
657 views

How long would it take to crack an 8-word brain wallet?

Assuming my private key for a bitcoin wallet is derived from SHA256(passphrase) and the passphrase is 8 words long, how long would it take the average attacker to crack my bitcoin wallet through a ...
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If SHA256 and/or RIPEMD-160 were broken, would all bitcoin addresses be compromised?

If not, what else would be needed to steal all funds from all people and completely break bitcoin? I bet some will say ECSDA gives bitcoin an additional layer of protection. I counter this by saying ...
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How can I convert a SHA256 hash into a Bitcoin base58 private key?

How can I take the output of sha256sum sudofox@ubuntu:~$ echo -n 'Hi guys!' | sha256sum 7542fb6685f9fd8f37d56faf62f0bb4563684a51539e4b26f0840db361e0027c - and turn it into a Base58Check encoded ...
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Why are hashes in the bitcoin protocol typically computed twice (double computed)?

According to the wiki specification of the bitcoin protocol, hashes are typically "computed twice". For example: hello 2cf24dba5fb0a30e26e83b2ac5b9e29e1b161e5c1fa7425e73043362938b9824 (first round of ...
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How do you perform double-SHA-256 encoding?

The Bitcoin Protocol-specification gives an example of double-SHA-256 encoding. hello 2cf24dba5fb0a30e26e83b2ac5b9e29e1b161e5c1fa7425e73043362938b9824 (first round of sha-256) ...
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How does a miner perform hashing?

I'm trying to walk my way through the process by which a miner hashes. Let's say the getwork request returns a data field of: ...
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Where can I see an input that will hash to a solution?

So as my understanding goes, there's some input (block header) that needs to be altered (via a nonce or other mechanism) which is run through a SHA256 to generate an output with X amount of leading ...
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870 views

Can an SHA256 hash be used as an ECDSA private key?

Is it possible to map a pass-phrase directly to a Bitcoin private key by using its SHA256 hash? I remember reading somewhere that not all 256 bit values are valid ECDSA private keys. If so, how can I ...
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Why are Bitcoin addresses hashes of public keys?

Currently, Bitcoin addresses and their checksums are constructed from the public key by a using repeated hashing with SHA256 and RIPEMD160. Now I understand the reasoning behind using hashing for ...
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287 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 ...