Chapter 7: Network security Foundations o what is security? o cryptography d authentication D message integrity o key distribution and certification Security in practice: O application layer: secure e-mail o transport layer: Internet commerce, SSL, SET D network layer: IP security 7: Network Security 17: Network Security 1 Chapter 7: Network security Foundations:  what is security?  cryptography  authentication  message integrity  key distribution and certification Security in practice:  application layer: secure e-mail  transport layer: Internet commerce, SSL, SET  network layer: IP security