Follow @Openwall on Twitter for new release announcements and other news
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Date: Mon, 19 Oct 2015 00:24:40 -0400
From: Alex Gaynor <>
To: "" <>
Cc: CVE ID Requests <>
Subject: Re: Prime example of a can of worms

I think we can have a far simpler rule: use of DH at <= 1024 bits gets a
CVE, the same way 512-bit RSA, or DES would.


On Mon, Oct 19, 2015 at 12:06 AM, Kurt Seifried <>

> So in light of:
> and
> I would suggest we minimally have a conversation about DH prime security
> (e.g. using larger 2048 primes, and/or a better mix of primes to make
> pre-computation attacks harder). Generating good primes is not easy from
> what I've seen of several discussions, my fear would be that people try to
> fix this by finding new primes that turn out to be problematic.
> Secondly I would also suggest we seriously look at assigning a CVE to the
> use of suspected compromised DH primes. Despite the fact we don't have
> conclusive direct evidence (that I'm aware of, correct me if there is any
> conclusive evidence) I think in this case:
> 1) the attack is computationally feasible for an organization with
> sufficient funding
> 2) the benefit of such an attack far, far, FAR outweighs the cost for
> certain orgs, from the paper:
> A small
> number of fixed or standardized groups are used by millions
> of servers; performing precomputation for a single 1024-bit
> group would allow passive eavesdropping on 18% of popular
> HTTPS sites, and a second group would allow decryption
> of traffic to 66% of IPsec VPNs and 26% of SSH servers.
> --
> Kurt Seifried -- Red Hat -- Product Security -- Cloud
> PGP A90B F995 7350 148F 66BF 7554 160D 4553 5E26 7993
> Red Hat Product Security contact:

"I disapprove of what you say, but I will defend to the death your right to
say it." -- Evelyn Beatrice Hall (summarizing Voltaire)
"The people's good is the highest law." -- Cicero
GPG Key fingerprint: 125F 5C67 DFE9 4084

Powered by blists - more mailing lists

Please check out the Open Source Software Security Wiki, which is counterpart to this mailing list.

Confused about mailing lists and their use? Read about mailing lists on Wikipedia and check out these guidelines on proper formatting of your messages.