1. KERBEROS

2. Introduction trusted key server system from MIT.Part of project Athena (MIT).Developed in mid 1980s. provides centralised private-key third-party authentication in a distributed network – allows users access to services distributed through network – without needing to trust all workstations – rather all trust a central authentication server Kerberos versions: – v1,v2,v3 already disappeared – v4 is widespread used, but there are some security flaws – v5 is the most recent version, more complicated

3. What is KERBEROS ? A computer network authentication protocol Provides a centralized authentication server to authenticate users to servers and servers to users in a secure manner Relies on conventional encryption, making no use of public-key encryption Prevents eavesdropping or replay attack Two versions: version 4 and 5 Version 4 makes use of DES

4. Why Kerberos? Sending usernames and passwords in the clear jeopardizes the security of the network. Each time a password is sent in the clear, there is a chance for interception.