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Re: [TLS] FNV versus SHA-1 in cached info

"Blumenthal, Uri - 0668 - MITLL" <uri@ll.mit.edu> Fri, 07 May 2010 18:50 UTC

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From: "Blumenthal, Uri - 0668 - MITLL" <uri@ll.mit.edu>
To: Nicolas Williams <Nicolas.Williams@oracle.com>
Date: Fri, 07 May 2010 14:50:37 -0400
Thread-Topic: [TLS] FNV versus SHA-1 in cached info
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Cc: Simon Josefsson <simon@josefsson.org>, "tls@ietf.org" <tls@ietf.org>
Subject: Re: [TLS] FNV versus SHA-1 in cached info
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Well, I have not seen a *convincing* rationale why cryptographically
unsuitable algorithms must not be used in non-cryptographic applications,
and I see no reason why formerly-cryptographic algorithms should be an
exception from the above.


On 5/7/10  13:28 , "Nicolas Williams" <Nicolas.Williams@oracle.com> wrote:

> On Fri, May 07, 2010 at 01:10:40PM -0400, Blumenthal, Uri - 0668 - MITLL
> wrote:
>> For cryptographic purposes agility is critical, and it's obvious.
>> 
>> For non-cryptographic purposes - who cares. Let the implementers figure what
>> works best and "codify" it. If it's SHA - fine. If it's FNV - fine. If it's
>> MD4 - fine. No sense avoiding cryptographically broken algorithms for
>> non-cryptographic use.
> 
> I agree, but it's important to have a rationale for this position.  I
> stated one.  Simon and others have stated rationales for the opposite
> position (that we should not use MD5 nor SHA-1 even when cryptographic
> properties are not required).
> 
> It'd be nice if we didn't have to revisit this every time someone needs
> a non-cryptographic hash function in an Internet protocol.
> 
> Nico

-- 
Regards,
Uri

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