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Re: Should openssl accept weak DSA/DH keys with g = +/- 1 ?

From: Jeffrey Walton <noloader () gmail com>
Date: Thu, 17 Apr 2014 15:22:04 -0400

On Thu, Apr 17, 2014 at 12:50 PM, Pavel Kankovsky
<peak () argo troja mff cuni cz> wrote:

Does anyone use non-safe primes for DH? Afaik any well-known moduli are
safe. And openssl dhparam generates safe primes only.

g = 2 is not a generator though its often used. Its possible to leak
information depending on parameter selection (or only generate half
the values of the group). See, for example, "Diffie-Hellman Parameter
Check (when g = 2, must p mod 24 == 11?)",
http://crypto.stackexchange.com/questions/12961/diffie-hellman-parameter-check-when-g-2-must-p-mod-24-11.

Jeff

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Current thread:

Should openssl accept weak DSA/DH keys with g = +/- 1 ? Georgi Guninski (Apr 15)
- Re: Should openssl accept weak DSA/DH keys with g = +/- 1 ? Hanno Böck (Apr 15)
  - Re: Should openssl accept weak DSA/DH keys with g = +/- 1 ? Georgi Guninski (Apr 16)
    - Re: Should openssl accept weak DSA/DH keys with g = +/- 1 ? Hanno Böck (Apr 16)
    - Re: Should openssl accept weak DSA/DH keys with g = +/- 1 ? Pavel Kankovsky (Apr 17)
    - Re: Should openssl accept weak DSA/DH keys with g = +/- 1 ? Jeffrey Walton (Apr 17)