Re: [TLS] Another IRINA bug in TLS

Tanja Lange <tanja@hyperelliptic.org> Fri, 22 May 2015 22:54 UTC

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Date: Sat, 23 May 2015 00:55:00 +0200
From: Tanja Lange <tanja@hyperelliptic.org>
To: Santiago Zanella-Beguelin <santiago@microsoft.com>
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Subject: Re: [TLS] Another IRINA bug in TLS
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Hi,
> > What testing do you do on unsafe primes?
> 
> We accept them if they're in the pre-populated cache. If not, we reject them
> because we can't check the order of the generator and validate ephemeral keys.
> Unsafe primes have other problems too, e.g. NFS pre-computation is a bit easier
> than for safe primes.
> 
What algorithm do you refer to here when you say that the NFS
precomputation gets easier. The only thing I know is that you
can solve the matrix modulo the group oder (or using fewer 
moduli when using CRT), but that's a very small speedup.

	Tanja