Techniques for binding multiple authentications for a peer are described. In one design, multiple authentications for the peer may be bound based on a unique identifier for the peer. The unique identifier may be a pseudo-random number and may be exchanged securely between the peer, an authentication server, and an authenticator in order to prevent a man-in-the-middle attack. Data for all authentications bound by the unique identifier may be exchanged securely based on one or more cryptographic keys generated by all or a subset of these authentications. In another design, multiple levels of security may be used for multiple authentications for a peer. The peer may perform a first authentication with a first authentication server and obtain a first cryptographic key and may also perform a second authentication with the first authentication server or a second authentication server and obtain a second cryptographic key. The peer may thereafter securely exchange data using the two keys using nested security.