Appendix B. Diffie-Hellman Groups

There are two Diffie-Hellman groups defined here for use in IKE. These groups were generated by Richard Schroeppel at the University of Arizona. Properties of these primes are described in [OAKLEY].

The strength supplied by group 1 may not be sufficient for typical uses and is here for historic reasons.

Additional Diffie-Hellman groups have been defined in [ADDGROUP].

B.1. Group 1 - 768-bit MODP

This group is assigned ID 1 (one).

The prime is: 2^768 - 2 ^704 - 1 + 2^64 * { [2^638 pi] + 149686 } Its hexadecimal value is:

FFFFFFFF FFFFFFFF C90FDAA2 2168C234 C4C6628B 80DC1CD1 29024E08 8A67CC74 020BBEA6 3B139B22 514A0879 8E3404DD EF9519B3 CD3A431B 302B0A6D F25F1437 4FE1356D 6D51C245 E485B576 625E7EC6 F44C42E9 A63A3620 FFFFFFFF FFFFFFFF

The generator is 2.

B.2. Group 2 - 1024-bit MODP

This group is assigned ID 2 (two).

The prime is 2^1024 - 2^960 - 1 + 2^64 * { [2^894 pi] + 129093 }. Its hexadecimal value is:

The generator is 2.

Kaufman, et al. Standards Track [Page 133] RFC 5996 IKEv2bis September 2010