Analysis of the DCS.v2 authentication protocol

Developers of the UF Distributed Conferencing System, version 2 (DCS.v2) have proposed a protocol that involves the distribution of a session key by a trusted server to a principal with whom it will communicate. The protocol differs from standard key exchange protocols in that it attempts to address the issue of the delivery of a private key as well as the desired session key in a secure fashion. Because of the complexity of asymmetric keys, it is necessary for human principals to store their private keys until needed. The DCS.v2 protocol assumes that principals encrypt their private keys and store them on a network. When they seek to communicate with other principals, they must request that the appropriate encrypted key be issued to them by the server which will in turn be used to decrypt the session key. This paper presents the protocol and analyses it using BAN logic.