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I am trying to find the average of hash rate (benchmark) for SHA-3(Shake128) for a normal and supercomputer in order to estimate the brute-force attack which I can get if from ( keyspace / hash rate )...then I found this website:

https://bench.cr.yp.to/results-hash.html

I could not understand these tables i.g. (Cycles/byte for 8 bytes) what do they mean by cycles/byte? Is it that hash rate for 8-bytes?

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Cycles per byte means the number of CPU cycles that must elapse in order to process a single byte of input for a specific processor. A CPU's clock frequency determines how many cycles per second the processor is running at (for example, 2.6 billion per second for a 2.6 GHz processor). Note that this is a rather crude type of benchmark, because the bottleneck may not be waiting for each instruction to retire. Memory access latency, shared resources, etc. can slow things down.

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  • $\begingroup$ Thanks for ur comment. Well, based on the table "x86; normally amd64; Sandy Bridge (206a7); 2011 Intel Core i3-2310M; 2 x 2100MHz; h6sandy, supercop-20171218" for "Cycles/byte for 8 bytes" shake128 is 540.50 so the hash rate is (540.50*8) right? please let me know if it is wrong. thanks $\endgroup$
    – Al-Ani
    May 8, 2018 at 4:24
  • $\begingroup$ Yes, assuming there are no other bottlenecks (like memory access latency) and it is processing 8 byte chunks at a time. Various optimizations may make it more efficient for different sizes, and of course that hash rate is specific to that CPU at the quoted frequency. $\endgroup$
    – forest
    May 8, 2018 at 5:54
  • $\begingroup$ And when they mentioned on the website 8-bytes they mean the output or the input?? like in my situation I have input 40-bits and the output is Shake128 $\endgroup$
    – Al-Ani
    May 8, 2018 at 6:26
  • $\begingroup$ I imagine 8 bytes is for the input. Different implementations may optimize for different input sizes, for example you might get away with 16- or 32-byte inputs if you are using a system that supports SIMD. $\endgroup$
    – forest
    May 8, 2018 at 6:28
  • $\begingroup$ Okay, well I got confused "I noticed that the hash rate getting less when the messages size increase". For example, shake128 for 8-bytes 540.50 while for 4096-bytes is 25.90. " $\endgroup$
    – Al-Ani
    May 8, 2018 at 6:48

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