What is unix, xauth, and des?

These are the three kinds of authentication:

• unix tells you the uid of the entity that is making an rpc call on you. The dbserver enforces security on each RPC call and uses this kind of authentication by default.

• xauth uses a read-protected file in your home directory to control access to your X display (and, thus, to your ttsession).

• des uses the Data Encryption Standard (DES) to ensure that processes who talk to ttsession are really who they say they are.