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Re: [TLS] SHA-1 vs. FNV-1

"Blumenthal, Uri - 0668 - MITLL" <uri@ll.mit.edu> Sun, 09 May 2010 21:20 UTC

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From: "Blumenthal, Uri - 0668 - MITLL" <uri@ll.mit.edu>
To: "'mike-list@pobox.com'" <mike-list@pobox.com>, "'ekr@rtfm.com'" <ekr@rtfm.com>
Date: Sun, 09 May 2010 17:19:44 -0400
Thread-Topic: [TLS] SHA-1 vs. FNV-1
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Subject: Re: [TLS] SHA-1 vs. FNV-1
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Mike is correct. As the risk of repeating myself: our current practice of using SHA-1 is dying just like the previous practice of using MD5 (and MD4 before it) is dead. So justifying continuous use of SHA-1 is improper: for security purposes it is broken, and for non-security purposes it's rather slow. The initial drive to move to SHA-1 was based solely on security needs and reasons - which do not apply any more. 

Need more be said?

Regards,
Uri

----- Original Message -----
From: tls-bounces@ietf.org <tls-bounces@ietf.org>
To: Eric Rescorla <ekr@rtfm.com>
Cc: tls@ietf.org <tls@ietf.org>
Sent: Sun May 09 17:07:18 2010
Subject: Re: [TLS] SHA-1 vs. FNV-1

Eric Rescorla wrote:
> 
> Really, given that the security analysis for why you don't need a secure
> hash needs to be written in any case, and that we're NOT using MD5
> but rather SHA-1, I don't see that the argument you're presenting
> for deviating from our standard SHA-1 using practice is compelling at
> all.

Won't there be a push to get rid of SHA-1 from protocols just as there
is for MD5 today?  It seems prudent NOT to use SHA-1 precisely for the
same reason we are not using MD5.

Mike
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