[7505] in cryptography@c2.net mail archive
Re: Elgamal
daemon@ATHENA.MIT.EDU (Greg Rose)
Wed Jul 19 18:21:08 2000
Message-Id: <4.3.1.0.20000720080233.00d424f0@127.0.0.1>
Date: Thu, 20 Jul 2000 08:05:27 +1000
To: "Simon Aronson" <sip99sma@rdg.ac.uk>
From: Greg Rose <ggr@qualcomm.com>
Cc: <cryptography@c2.net>
In-Reply-To: <LPBBJMPLENMBOGLLMBNMCEDBCAAA.sip99sma@rdg.ac.uk>
Mime-Version: 1.0
Content-Type: text/plain; charset="us-ascii"; format=flowed
At 21:02 00/07/19 +0100, Simon Aronson wrote:
>In an implementation of the ElGamal cryptosystem, is it acceptable to always
>use the same prime and generator for every transmission? Or should a new
>prime/generator pair be chosen for each communication?
Yes, in fact you pretty much have to, since they are used to create the
public key from the private key. Except for creating a very big target,
there's no real reason why eveyone shouldn't share the same prime and
generator; IPSec standardises a couple (of different sizes).
Greg.
Greg Rose INTERNET: ggr@Qualcomm.com
Qualcomm Australia VOICE: +61-2-9181-4851 FAX: +61-2-9181-5470
Suite 410, Birkenhead Point, http://people.qualcomm.com/ggr/
Drummoyne NSW 2047 232B EC8F 44C6 C853 D68F E107 E6BF CD2F 1081 A37C
