Diffie–Hellman

Walks through a Diffie–Hellman exchange step by step: a public prime p and generator g (presets from 23 to 7919, or custom), Alice's and Bob's random secrets a and b, the public values g^a and g^b mod p, and the shared secret g^ab mod p both compute. Whitfield Diffie and Martin Hellman published the method in “New Directions in Cryptography” (1976); RFC 7919 defines groups of 2048 to 8192 bits.

• W. Diffie and M. E. Hellman, “New Directions in Cryptography”, IEEE Transactions on Information Theory 22 (6), 1976, pp. 644–654
• RFC 7919, Negotiated Finite Field Diffie-Hellman Ephemeral Parameters for Transport Layer Security (TLS) (2016)