Verification of primes in /etc/ssh/moduli file

Damien Miller djm at
Sat Aug 21 20:06:52 AEST 2021

On Wed, 18 Aug 2021, Hubert Kario wrote:

> Hello everybody!
> For the past few years we've used a tool to double-check the security of
> the primes shipped in the OpenSSH moduli file:
> In short, it uses primality certificates to mathematically prove that all 
> the 
> parameters use safe primes and a bit of simple maths to check if they're 
> not
> vulnerable to Special Number Field Sieve.
> I wrote an article on why it's necessary, a high level overview how it
> does it and how you can run it yourself:

Excellent - one question: how do you generate/prove safe primes? I was
never able to figure out how to prove that both N and (N-1)/2 are prime
(though I thought it might be possible using Pocklington's criteria).


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