Verification of Correspondence Assertions in a Calculus for Mobile Ad Hoc Networks

We introduce a novel process calculus called DBSPI (distributed broadcast SPI-calculus) which models mobile ad hoc networks (MANET). The calculus is a cryptographic broadcast calculus with locations and migration. Communication and migration are limited to neighborhoods. Neighborhood definitions are explicitly part of the syntax allowing dynamic extension using bound identifiers. In this semantic setting we study authentication of agents in MANET protocols. A safety property dealing with authentication correspondence assertions is defined. Later a dependent type and effect system is given and it is shown to be sound, i.e. protocols which are typeable are also safe. This result is lifted to open systems which involves Dolev-Yao attackers. Our Dolev-Yao attacker may use public keys for encryption and can attack any neighborhood it wishes. Our technique is applied to the Mobile IP registration protocol – a type check shows it is safe. To our knowledge this is the first type system for a MANET calculus doing that.