Diffie-Hellman Knows ga, gb, g, and p So we want to find the key k b This is believed to be hard If one knows how to compute discrete logs efficient ntly then one can break this scheme (and other schemes based on public key cryptography)8 • Knows g a , gb , g, and p • So we want to find the key, k – k = gab – This is believed to be hard. • If one knows how to compute discrete logs efficiently, then one can break this scheme (and other schemes based on public key cryptography) Diffie-Hellman