SHA-512 is 1.5x faster than SHA-256 on 64-bit platforms

#1

Post by steffenweber » Wed, Feb 01, 2017, 11:07 PM UTC

SHA-512 is 1.5x faster than SHA-256 on 64-bit platforms
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Re: SHA-512 is 1.5x faster than SHA-256 on 64-bit platforms

#2

Post by dchest » Thu, Feb 02, 2017, 12:49 AM UTC

Similarly:

    BLAKE2s (32-bit words) - 554 MiB/s
    BLAKE2b (64-bit words) - 890 MiB/s

(source: https://blake2.net/)

The difference is also clear in pure JavaScript implementations — JS doesn't have native 64-bit integer operations yet, so SHA-512 is slower there:

   SHA-256 - 103.17 MiB/s
   SHA-512 -  34.29 MiB/s

Note that since SHA-512 eats 128-byte blocks, while SHA-256 64-byte blocks, hashing very short strings may be faster with SHA-256 even on 64-bit platforms (the same applies to BLAKE2).

Re: SHA-512 is 1.5x faster than SHA-256 on 64-bit platforms

#3

Post by loeg » Thu, Feb 02, 2017, 1:13 AM UTC

Yep. Taking advantage of SHA512's superior performance while still producing a 256 bit result is the raison d'être of SHA-512/256.

Re: SHA-512 is 1.5x faster than SHA-256 on 64-bit platforms

#4

Post by [deleted] » Thu, Feb 02, 2017, 1:33 AM UTC

[deleted]

Re: SHA-512 is 1.5x faster than SHA-256 on 64-bit platforms

#5

Post by nstr10 » Thu, Feb 02, 2017, 3:17 AM UTC

I would be curious to see this compared with SHA-384, and across multiple languages.

Re: SHA-512 is 1.5x faster than SHA-256 on 64-bit platforms

#6

Post by hyh1048576 » Thu, Feb 02, 2017, 3:18 AM UTC

As a side note, there are some cryptocurrency project using half of the sha512, since it's faster and using a 256 bit hash saves spaces.

Re: SHA-512 is 1.5x faster than SHA-256 on 64-bit platforms

#7

Post by joshuak » Thu, Feb 02, 2017, 3:29 AM UTC

We use this fact in our ID system. Consider bloom filters... so many different 'hash functions' you get for free out of 64 bytes of hash data.

Re: SHA-512 is 1.5x faster than SHA-256 on 64-bit platforms

#8

Post by cperciva » Thu, Feb 02, 2017, 3:34 AM UTC

nstr10 wrote: post #5

I would be curious to see this compared with SHA-384, and across multiple languages.

SHA-384 is exactly the same speed as SHA-512. SHA-512/256 is also the same speed -- it's basically SHA-512 with the output truncated to 256 bits.

Re: SHA-512 is 1.5x faster than SHA-256 on 64-bit platforms

#9

Post by meta_AU » Thu, Feb 02, 2017, 3:57 AM UTC

loeg wrote: post #3

Yep. Taking advantage of SHA512's superior performance while still producing a 256 bit result is the raison d'être of SHA-512/256.

Well... only if you ignore the advantages of immunity to length extension.

Re: SHA-512 is 1.5x faster than SHA-256 on 64-bit platforms

#10

Post by shakna » Thu, Feb 02, 2017, 5:53 AM UTC

dchest wrote: post #2

Similarly: BLAKE2s (32-bit words) - 554 MiB/s BLAKE2b (64-bit words) - 890 MiB/s (source: https://blake2.net/ ) The difference is also clear in pure JavaScript implementations — JS doesn't have native 64-bit integer operations yet, so SHA-512 is slower there: SHA-256 - 103.17 MiB/s SHA-512 - 34.29 MiB/s Note that since SHA-512 eats 128-byte blocks, while SHA-256 64-byte blocks, hashing very short strings may be faste…

> in pure JavaScript implementations

Is not JS cryptography a bad idea?