openwall / openwall/john

Should --cost items be audited

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Description

As I have found out, ,doing a comprehensive check of gpg, the -cost items do not always go from quicker to slower. Here is a grid showing speeds with a mix of all cost2/cost3 values The vertical grid is hash type, and the horizontal is encryption type. Both are in order by 'cost' numbers, but as can be seen,

. idea 3des cast5 bf a128 a192 a256 2f c128 c192 c256
md5 52.1 24.6 49.4 40.8 51.5 25.5 25.4 21.8 53.3 25.7 25.6
sha1 41.6 20.7 41.7 33.2 40.2 20.8 20.5 19.9 40.7 20.8 20.7
ripmd 19.7 10.0 20.0 18.5 19.3 8.8 9.3 8.5 18.2 9.5 10.0
s256 20.7 19.8 20.8 18.3 20.9 20.2 20.7 19.8 20.4 18.4 20.5
s384 27.2 27.4 27.6 24.0 27.8 28.4 28.8 27.6 26.4 26.9 27.3
s512 27.5 28.5 28.7 24.5 27.6 27.8 28.4 27.3 28.5 27.1 26.5
s224 17.9 19.7 19.6 17.1 19.8 19.6 10.1 9.9 20.1 20.2 9.8

Is there anything we can (or should) do to help normalize how cost works ? I am sure there are other formats which the --cost values do not line up with throughput.

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Research direction

No source file, test, or entry point is named. Begin by reproducing the reported gpg benchmark grid and examining how cost2 and cost3 values are assigned across hash and encryption types; done requires an agreed way to audit or normalize cost ordering without losing the reported throughput data.

Written by the indexing model from the issue text.

Assessment

Tech stack
c
Domain
cryptography, performance
Issue type
Feature
Difficulty
5/5
Estimated time
Over a week
Activity status
Stale
Clarity
Needs clarification
Newbie friendliness
25/100

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