Re: Hash algorithm analysis

From: Junio C Hamano <gitster@pobox.com>
Date: Jul 24, 2018, 21:13 UTC
Message-ID: <xmqqzhygwd5o.fsf@gitster-ct.c.googlers.com>
In-Reply-To: <CA+55aFwSe9BF8e0hLk9pp3FVD5LaVY5GRdsV3fbNtgzekJadyA@mail.gmail.com>

Linus Torvalds <torvalds@linux-foundation.org> writes:

Show 12 quoted lines

> On Tue, Jul 24, 2018 at 12:01 PM Edward Thomson
> <ethomson@edwardthomson.com> wrote:
>>
>> Switching gears, if I look at this from the perspective of the libgit2
>> project, I would also prefer SHA-256 or SHA3 over blake2b.  To support
>> blake2b, we'd have to include - and support - that code ourselves.  But
>> to support SHA-256, we would simply use the system's crypto libraries
>> that we already take a dependecy on (OpenSSL, mbedTLS, CryptoNG, or
>> SecureTransport).
>
> I think this is probably the single strongest argument for sha256.
> "It's just there".

Yup. I actually was leaning toward saying "all of them are OK in practice, so the person who is actually spear-heading the work gets to choose", but if we picked SHA-256 now, that would not be a choice that Brian has to later justify for choosing against everybody else's wishes, which makes it the best choice ;-)