[42889] in Cypherpunks
Re: Photuris Primality verification needed
daemon@ATHENA.MIT.EDU (Hilarie Orman)
Sat Nov 4 21:32:03 1995
Date: Sat, 4 Nov 1995 19:29:10 -0700
From: Hilarie Orman <ho@cs.arizona.edu>
To: bsimpson@morningstar.com
Cc: cypherpunks@toad.com, ipsec-dev@eit.COM
In-Reply-To: Yourmessage <1973.bsimpson@morningstar.com>
> Recently, someone asked for a smaller prime of only 512-bits for speed.
> This is more than enough for the strength of keys needed for DES, 3DES,
> MD5 and SHA. Perhaps this would be easier to have more complete and
> robust verification as well.
Depending on what you think of the strength of those algorithms, the 512-bit
mod p system may not be strong enough.
The *strength* of 512-bit mod p DH systems is only about 56 bits. You need
1024-bit primes for a *strength* of 80 bits.
In contrast, the 155-bit elliptic curve in the Photuris draft has a
strength of about 76 bits.
