Tagged Questions

A hash is a mathematically reproducible but irreversible process which takes one value as an input and predictably produces a derived value as an output. Hashing is central to Bitcoin mining as well as the generation of Bitcoin addresses.

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36 views

How can I mine ALT SHA-256 coins using a Bitmain S4?

The bitmain S4 does 2TH/s out of the box with no overclocking. For many alt SHA-256 coins, this can be 10% - 50% of the entire network hashing power, which would allow us to gain alt coins quickly, ...
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0answers
32 views

How do satoshidice's draws work? (HMAC hashes)

I am trying to understand how does a satoshidice draw work. As far as i have understood satoshidice generates daily two public hashes: HMAC hash (H from here on) Position hash (P grom here on) ...
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1answer
70 views

What does it mean for a cryptocurrency to be ASIC-resistant?

I guess the question I'm asking here is what does it take for an altcoin to be ASIC-resistant? What does it need to have?
2
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1answer
37 views

Proof of work - does the equipment matter?

It technically doesn’t matter whether I am using a super computer or a laptop to do the proof of work, it’s simply that with a super computer I can go through the attempts much faster, which means I ...
2
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2answers
63 views

SHA256 * 2 on header - what am I doing wrong?

I've been experimenting with the php code here: https://en.bitcoin.it/wiki/Block_hashing_algorithm (after correcting the small bug of $x=; to $x=""; ) With these blocks 0 and 125552 (for example) it ...
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1answer
122 views

How does a proof of work limit of `~uint256(0) >> 20` translate into a difficulty of `1 / 2^12`?

In the Litecoin source it is written: static CBigNum bnProofOfWorkLimit(~uint256(0) >> 20); // Litecoin: starting difficulty is 1 / 2^12 How does that compute? ~uint256(0) >> 20 is ...
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2answers
111 views

What is the average number of hashes it takes to mine bitcoins?

I'm just curious about this. I'm not sure if the length of zeros in the hash result is directly proportional to the probability, or how to calculate this.
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0answers
17 views

mining pcie 16x and 1x together caused rejects

I have 5 msi radeon R9 290 cards and this board https://www.asus.com/Motherboards/Z87PLUS/specifications/ . With 3 pcie 16x everything runs smooth but, as soon as I add the first 1x into the equation, ...
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0answers
868 views

BFGminer can't find my NanoFury on Raspberry Pi

Related: BFGminer can't find my NanoFury! Posted on the RPi Exchange as well http://raspberrypi.stackexchange.com/questions/14753/bfgminer-cant-find-my-nanofury-on-raspberry-pi Forums: ...
0
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1answer
90 views

How accurate should pool estimation of hashing speed be?

I'm playing around with a few USB miners, and am running 4 of them for a total of 4.6 GH/s. My BTCGuild dashboard estimation is all over the place, sometimes 1 GH/s, sometimes as high as 3.8 GH/s. ...
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2answers
48 views

Required number of bits in nonce [duplicate]

Is there a formal proof that with N bits to iterate in the nonce of the block, a hash satisfying proof of work will be ever found? How large that N (number of bits in the nonce) should be to satisfy ...
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1answer
84 views

Can mining puzzles be made socially valuable? [duplicate]

Bitcoin miners work to solve a random puzzle as "proof of work". A huge amount of raw computing power is going into finding the solution to these puzzles, yet the actual solution to the puzzle serves ...
0
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2answers
106 views

Would it be possible to have an ARM hashing based Cryptocurrency?

This was something that popped into my mind while I was thinking about CPU Only Alt-coins. Would it be possible to have an ARM-based coin? That is, a coin that could only be mined on ARM devices ...
0
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1answer
807 views

Effect of internet connection speed on solo mining [duplicate]

I have a set of PCs hasing at 100 kH/s and currently the network difficulty is 2674.36329706. My power usage is 200 W, and as per ...
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3answers
174 views

Does a miner (or mining pool) who has 10x as much hashing power have 10x the odds of mining a block?

I heard somewhere that joining a mining pool logarithmically increases your odds of mining a block.. is that for some reason true? Or was it someone who didn't know what they were talking about and ...
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2answers
343 views

Can you help with Bitcoin block hashing algorithm ( PHP, C, Python, Javascript)? [closed]

can you help with Bitcoin block hashing algorithm ( PHP, C, Python, Javascript) ? I was working really hard to write block hashing algorithm in plain Javascript. Unfortunately the developed ...
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0answers
9k views

What is the conversion then for MH/s to GH/s and so on [duplicate]

I've seen this answer and maybe I'm just tired What is the difference between KH/s MH/s GH/s? 1 kH/s is 1,000 hashes per second (sometimes mistakenly written KH/s). 1 MH/s is 1,000,000 ...
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1answer
127 views

Block Hashing Data

Guys I have a few points that are not clear for me. 1) In the link below it says there are some fields we have to combine and hash. However when I get a work by saying getwork from a pool. What I get ...
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1answer
303 views

What is the approximate hashrate of a human?

Which and how much mathematical operations are required for the blockheader-to-blockhash operation and how fast would a human be able to calculate a single hash? EDIT: For simplicity, I think it's a ...
3
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5answers
851 views

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

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 ...
2
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2answers
5k views

What is the relationship between hash rate and accepted shares?

Specifically this question is about Litecoin, but I suspect the answer would apply to both. Say you have a rig mining at 700Kh/s (LTC). It seems that you get, more or less, a one or a few accepted ...
2
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2answers
99 views

How large can the bitcoin salt value be?

To mine bitcoin I believe that you take the input and add a salt number to that then run the hashing algorithm to find a suitable output, but how large can the salt be, couldn't I just take the ...
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4answers
4k views

BFGminer can't find my NanoFury!

I recently purchased a Nanofury ASIC unit. I tried running it on my Linux system, as I just let the computer sit and run. I couldn't get it to work on Linux, so I decided to give it a try on Windows = ...
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2answers
2k views

When mining with 2 computers, do I need to use 2 separate wallets addresses?

I understand that each miner is working on a different block. Correct me if I'm wrong but this is because the first transaction in a block basically contains my wallet address so I can receive the ...
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1answer
107 views

Can an old block be inserted into the blockchain?

I've been shown how network time is enforced, but I'm still having trouble understanding how a false old block cannot be inserted into the blockchain with the entire chain remined or how a powerful ...
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1answer
117 views

The bitcoin address space seems to be closer to 2^40, not 2^160

The Base58 Encoding of a public key hash outputs: "A set of 58 alphanumeric symbols consisting of easily distinguished uppercase and lowercase letters (0OIl are not used)" This set is a fixed string ...
1
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1answer
108 views

Are transactions still tamper-proof if blocks are hashed without nonces?

If an alt were to forgo difficulty and timed release of new supply by removing the nonce from blocks therefore the whole difficulty/target system, is hashing without nonces still providing the same ...
0
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1answer
317 views

Mining a primecoin based currency (datacoin). How do I find out how much hash power im doing?

How do I find out how much hashing power am I providing to the network? What is the command to find it out? Currently I see this: http://prntscr.com/2cd3zo when I run: watch 'datacoind ...
1
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1answer
134 views

Why are blocks hashed?

Am I correct that addresses are hashed to compress a huge text-represented coprime into something of manageable size? Am I also correct that transactions are hashed for the same reason and also ...
1
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1answer
10k views

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 ...
1
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4answers
3k views

Alternative Cloud Hashing sites to Cex.io [closed]

I am really impressed with Cex.io and their whole concept of trading Ghs for Bitcoin as well as cloud mining which I find to be novel and interesting. Are there any other sites like that? I know ...
0
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2answers
7k views

Will the 3TH KNC Neptune Miner still be profitable in 2014?

I am seriously considering making an investment and buying a 3TH miner. The problem is whether they will still be profitable by the time they arrive... At today's has rate calculation of 707,408,283 ...
0
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1answer
2k views

Quarkcoin money supply and hashing

If the money supply of Quarkcoin is 257 million QRK, what will be the incentive for miners to mine 1 million coins a year? What does it mean for the currency if almost nobody is mining it? Also why ...
4
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2answers
389 views

How do signatures work?

Just curious, if I send a transaction from one address to another, how do they verify it without knowing my private key?
3
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1answer
94 views

Is the idea of a “honey hole” such as in gold mining, present in bitcoin mining?

I understand the output of the SHA-256 hashing function is a random number between 0 and 2^256. Does the randomness of this output imply that there cannot be a, so to say, honey hole in the hashing. ...
1
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1answer
310 views

Cheating ASICs and Mining Software

I've noticed the recently solved block hashes have started with a number of zeros (8 last time I checked). Couldn't we just tell our mining hardware/software to assume the first few digits are in fact ...
5
votes
1answer
8k views

What do `minerd`s feedback messages (LONGPOLL, yay, boo) mean?

I have been testing a script that essentially runs (incomplete command shown here!): minerd --algo scrypt -s 45 --retry-pause 5 --threads $threads --url ... Among the feedback messages, while minerd ...
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1answer
892 views

Bitcoin block hashing algorithm. nonce

Referencing the Bitcoin wiki, what is the auhoritative source for providing a hash of the previous block? Or do miners keep listening to latest blocks? How is hash of the Merkle root generated? Can ...
2
votes
1answer
575 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 ...
2
votes
2answers
430 views

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 ...
2
votes
3answers
753 views

What is the problem that mining solves?

Of course, the function of mining is to secure the blockchain, but I'm looking for a more abstract summary of what the exact problem is that mining tries to solve? I believe its called the Byzantine ...
0
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1answer
14k views

Can I use bitcoin USB block erupters to mine litecoin? [duplicate]

Let's say I buy a USB block erupter, can I use the same to mine Litecoins? Does it require special software and setup to mine Litecoins?
7
votes
3answers
865 views

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 ...
2
votes
2answers
188 views

What is wrong with using hmac_sha512(block_hash, trans_id) as the resulting hash for a provably fair game?

Let's assume someone wants to make their own version of Satoshi Dice. Satoshi Dice states that the winning output of the game is determined in the following manner. The lucky number used to ...
1
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1answer
611 views

Why do we need a mining speed above 4.3Ghash/s?

I believe there will be a simple flaw in my understanding somewhere. From what I can tell for any given block you increment a nonce up to 2^32 (4294967296) per second (and the timestamp every second) ...
7
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1answer
465 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 ...
0
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0answers
106 views

Salted decryption

One of my buddies on the programming team on my robotics team gave me a message worth one Bitcoin. The message was to be converted into an SHA-256 hash. This SHA-256 hash is also salted, and as such I ...
1
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1answer
189 views

Difference between coinbaseaux.flags vs. coinbasetxn.data?

After reading through most of the protocol, and trying to piece everything together, I'm still at a loss as to how some things work. For example, the difference between coinbaseaux.flags and ...
0
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2answers
816 views

How to hash data from 'getblocktemplate' request

I've been reading lots of articles, trying to understand how to hash the data returned from getwork; but I totally overlooked getblocktemplate. I'm just trying to understand how all the data below is ...
6
votes
1answer
437 views

How to 'attach' metadata to a bitcoin receive address

I need to generate a receive address that is directly associated with some metadata, M, that forms part of a verifiable contract. I require that customers can verify that an address really was ...