> I'm proposing it is time to change this to MUST NOT for 4307bis.
+1 On 09/10/16 23:26, "IPsec on behalf of Paul Wouters" <ipsec-boun...@ietf.org on behalf of p...@nohats.ca> wrote: > >Released a few days ago: > > http://eprint.iacr.org/2016/961 > > A kilobit hidden SNFS discrete logarithm computation > Joshua Fried and Pierrick Gaudry and Nadia Heninger and Emmanuel Thomé > > We perform a special number field sieve discrete logarithm > computation in a 1024-bit prime field. To our knowledge, this > is the first kilobit-sized discrete logarithm computation ever > reported for prime fields. This computation took a little over > two months of calendar time on an academic cluster using the > open-source CADO-NFS software. > >Basically, this paper shows how to make a DH group of 1024 modp >with a backdoor, in two months of academic computing resources, > >The paper mentions 5114 a few times: > > RFC 5114  specifies a number of groups for use with > Diffie-Hellman, and states that the parameters were drawn > from NIST test data, but neither the NIST test data  nor > RFC 5114 itself contain the seeds used to generate the finite > field parameters > >And concludes: > > Both from this perspective, and from our more modern one, dismissing the > risk of trapdoored primes in real usage appears to have been a mistake, > as the apparent difficulties encountered by the trapdoor designer in >1992 > turn out to be easily circumvented. A more conservative design decision > for FIPS 186 would have required mandatory seed publication instead of > making it optional. As a result, there are opaque, standardized >1024-bit > and 2048-bit primes in wide use today that cannot be properly verified. > >This is the strongest statement yet that I've seen to not trust any >of the RFC-5114 groups. > >The latest 4307bis document has these groups (22-24) as SHOULD NOT, >stating: > > Group 22, 23 and 24 or 1024-bit MODP Group with 160-bit, and > 2048-bit MODP Group with 224-bit and 256-bit Prime Order Subgroup > have small subgroups, which means that checks specified in the > "Additional Diffie-Hellman Test for the IKEv2" [RFC6989] section > 2.2 first bullet point MUST be done when these groups are used. > These groups are also not safe-primes. The seeds for these groups > have not been publicly released, resulting in reduced trust in > these groups. These groups were proposed as alternatives for > group 2 and 14 but never saw wide deployment. It is expected > in the near future to be further downgraded to MUST NOT. > >I'm proposing it is time to change this to MUST NOT for 4307bis. > >Possibly, we should do this via SAAG in general, and then follow SAAG's >advise in IPSECME. > >Is there _any_ reason why group 22-24 should not be MUST NOT ? > >Paul > >_______________________________________________ >IPsec mailing list >IPsec@ietf.org >https://www.ietf.org/mailman/listinfo/ipsec _______________________________________________ IPsec mailing list IPsec@ietf.org https://www.ietf.org/mailman/listinfo/ipsec