Subject: Re: nsec2 large label pain

From: Simon Josefsson <[email-masked]>
Date: Mon, 24 May 2004 16:54:30 +0200

Marcos Sanz/Denic <[email-masked]> writes:

> SHA-256 still works, though. Do we need something bigger?

Considering that the strongest signature algorithm specified uses
SHA-1 today, I suspect it is not an immediate concern, at least.

Also, I don't know whether the attacks that are enabled if you even
truncate the hash values are serious.  That is, answer this question:
if you truncate the hash to, say, 64 bits, what can an attacker do?
Truncate to 32 bits?  It seems non-obvious that this can be abused in
any useful way, but I may be missing something.

Regards,
Simon

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From: Ben Laurie <[email-masked]>
Date: Mon, 24 May 2004 18:07:39 +0100

Marcos Sanz/Denic wrote:
>>Base64 encoding is not possible for a label due to canonicalizing. The
>>best one can do is base32 encoding (62.5%).
> 
> 

SHA-1 means that for a 1 in 2 chance of a single collision, you need 
around 10^24 names. I imagine that makes it sufficient for now?

I could add SHA-256 as an option. Fine by me.