Third European Symposium on Research in Computer Security (ESORICS 94)
Designing Secure Key Exchange Protocols
Colin Boyd, Wenbo Mao
Keywords : Cryptographic protocols, key management, authentication
Abstract : Protocols for authentication and key exchange have proved difficult to develop correctly despite their apparent simplicity in terms of the length and number of messages involved. A number of formal techniques have been developed to help analyse such protocols and have been useful in detecting errors. Nevertheless it is still difficult to be certain that a particular protocol is correct. This paper explores a different approach; instead of analysing existing protocols the aim is to design protocols to be secure in the first place. A methodology is developed for designing key exchange protocols in a restricted way such that they must be correct according to a defined security criterion. The protocols are defined abstractly with the cryptographic operations specified only according to their basic functions. This allows the protocols to be made concrete in a variety of ways. A number of concrete protocols are presented, some of which appear novel and, at the same time, efficient in comparison with existing ones.
(Pages 93-105)