The context of Cryptography, introduction of Cryptography, Massage security, block chipper mode, hash fungtions, Message autentications codes, the secure channel, implementaions issuees, key negotiations, generating randomness, primes, diffie-hellman, RSA, introductions cryptography protocols, Key Negitiations, key management, the clock, key servers, the dream of PKI,PKI Relity, PKI practicalit…