Re: Hash algorithm analysis
- From
- David Lang <david@lang.hm>
- Date
- Jun 12, 2018, 00:11 UTC
- Message-ID
- <alpine.DEB.2.02.1806111708540.23278@nftneq.ynat.uz>
- In-Reply-To
- <878t7kx5t3.fsf@evledraar.gmail.com>
On Tue, 12 Jun 2018, Ævar Arnfjörð Bjarmason wrote:
Show 8 quoted lines
>> From a performance standpoint, I have to say (once more) that crypto >> performance actually mattered a lot less than I originally thought it >> would. Yes, there are phases that do care, but they are rare. > > One real-world case is rebasing[1]. As noted in that E-Mail of mine a > year ago we can use SHA1DC v.s. OpenSSL as a stand-in for the sort of > performance difference we might expect between hash functions, although > as you note this doesn't account for the difference in length.
when you are rebasing, how many hashes do you need to calculate? a few dozen, a few hundred, a few thousand, a few hundered thousand?
If the common uses of rebasing are on the low end, then the fact that the hash takes a bit longer won't matter much because the entire job is so fast.
And at the high end, I/O will probably dominate.
so where does it really make a human visible difference?
David Lang