Bitcoin Sign up or log in to customize your list._ Here's how it works: Anybody can ask a question Anybody can answer The best answers are voted up and rise to the top up vote 2 down vote favorite I am in the process of designing a cryptographic Proof of Storage (PoS) that relies on single threaded computation of SHA256 hashes.In practice, my algorithm is equivalent to computing for some string S the value SHA256^N(S) = SHA256(SHA256(SHA256(...(SHA256(S)))).This forces anything computing that function to use only one thread, as each SHA256 step needs the output of the previous as input.Now, I know that ASIC miners exist that can compute SHA256 hashes at an enormous rate.This, however, is due to their parallelism: completing Proofs of Work (i.e., finding zeros of hash functions) is an embarassingly parallel problem and can be computed very fast on massively parallel devices.This is not what I am looking for.What I am looking for is the fastest device that would be able to compute my function, i.e., single-threaded computation of a SHA256, then the SHA256 of its output, the SHA256 of the result and so on.

I thought that maybe in this case the best hardware would be the fastest CPU in terms of single threaded performance: I found here that Intel Core i7-7700K could be a good place to start looking for.Is there any other known specialized hardware device that could carry out the task faster?mining-hardware sha256 altcoin-development up vote 1 down vote Well, existing Bitcoin mining hardware would indeed not be any good for iterated hashing, as it's not designed to do that.bitcoin diario la nacionHowever, SHA-256 is not a hardware resistant hash function.bitcoin irvineThe most complex operation in the hash function is addition modulo 2³², which is quite easy to implement in hardware.ethereum chain download

An attacker could implement a fast SHA core on a chip, which would consist of calculating a single round as fast as possible.This is the opposite optimization as a Bitcoin miner: miners prefer very many parallel cores that run at slower clock speeds to save energy per hash.Such a hypothetical chip would definitely be much faster than a CPU at calculating iterated hashes.What you want is a memory-hard hash function such as Argon2.Its execution requires fast cache, which is plentiful on commodity CPUs but costly to build into other hardware.bitcoin temple barIt has a parallelism parameter where you can allow up to, say, 4 cores.comprar bitcoin facilmenteIteration of the function will not be any faster past that number of cores, and custom hardware will not increase the attacker's speed.titan coin bitcoin

up vote 1 down vote maservant is correct that you could build specialized hardware to compute this faster.I'm assuming that you're interested only in off-the-shelf hardware.Intel has proposed adding SHA256 extensions to their CPU's to make them able to compute SHA256 faster.None of those are currently on the market, but unconfirmed speculation says that Cannonlake CPU's will have the SHA instructions.(You can check if a CPU supports these by running cpuid | grep SHA.)Also, you're using the CPU in a somewhat unusual way.For example, most workloads don't fit in L1 cache, so they benefit from better and more cache.That won't matter at all to you.Some aspects of SHA256 can be parallelized.For example, the compression function and the message expansion can be run at the same time.I think, but am not sure, that it's also possible to get some degree of parallelism between SHA256 compression rounds.Notice that the only variables that change as a result of the computation are A and E; all the rest are just shifted over one space.

You may want to consider overclocking the CPU to a degree that would make most systems unstable.While computing repeated SHA256 requires fast serial performance, verifying it can be done in parallel.I'm very curious about what you're building, and why this is relevant to it.Your Answer Sign up or log in Sign up using Google Sign up using Email and Password Post as a guest Name Email discard By posting your answer, you agree to the privacy policy and terms of service.Not the answer you're looking for?Browse other questions tagged mining-hardware sha256 altcoin-development or ask your own question.ASIC miners are the closest you will ever be to a money machine!These beasts of power and efficiency are the most popular type of mining device right now and their popularity and demand remain as high as in the day they showed up.Once we arrived to the Application Specific Integrated Circuit (ASIC) era, we knew we couldn’t go back.No, we didn’t want to go back!

It doesn’t get any better than with ASIC chips, the technology specially designed to mine Bitcoins.It’s rumored that one of these miners was recently sold for $20,000 USD on Ebay.Ot might be just gossip, but the real truth is that ASIC miners are the icing on the cake.Today, ASIC means business and profit and we are here to show you some of the best miners out there.With an amazing 500 gigahashes per second of efficiency, this ASIC mining rig from Butterfly Labs was first seen working in June.The new Single Bitforce SC (Super Computer) can produce 60 gigahashes per second, consuming around 270W while running at the top of its speed.This modular system with ASIC processors was the first ASIC Bitcoin mining hardware being shipped by BitSynCom LCC.The Avalon V1 motherboard has four hashing units, which would account for approximately 89 gigahashes per second.This ASIC mining rig created by Butterfly Labs took a while to be delivered, but once it finally arrived it proved to be a good investment.