[cap-talk] FW: x.509 -- MD5 considered harmful today

[Bill Frantz]

zooko at zooko.com (zooko) on Wednesday, December 31, 2008 wrote:

>On Dec 31, 2008, at 15:20 PM, Bill Frantz wrote:
>
>> In my experience, the code which performs the I/O is frequently  
>> expensive enough to be a bottle neck. Many compression functions  
>> can pay for themselves by reducing the CPU cost of the I/O. How do  
>> these hash functions compare in CPU cost with common compression  
>> functions?
>
>
>Secure hash functions are more expensive.  SHA-256 is about 21 cycles  
>per byte.  The fastest open source compression (multi-algorithm, type- 
>detecting) that I know of -- FreeARC -- is about 3.7 cycles per  
>second (on a standard test set).  zlib is about 16 cycles per byte.
>
>I'm hoping that SHA-3 will turn out to be substantially faster than  
>SHA-256, but it might not be.

<http://skein-hash.info/sha3-engineering> shows a number of SHA-3
candidates the Skein builders consider "good" which are under 10
cycles/byte, so it is likely you wish will be granted.

Cheers - Bill

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