Outline for April 27, 2000

1.	Authentication protocols?

a.	classical: need trusted third party for both secrecy, authentication

b.	public key: need to verify to whom public key belongs

2.	Challenge-response

a.	UNIX passwords

b.	Kerberos

c.	S/Key

d.	Diffie-Hellman and Sun's Secure RPC

3.	Public key

a.	Standard: encipher with private key, decipher with public key

b.	Binding public keys to identity: certificates

c.	X.509, PGP web of trust

d.	PEM hierarchy of certification