Broadcast Abstraction in a Stochastic Calculus for Mobile Networks

International audienceWe introduce a continuous time stochastic broadcast calculus for mobile and wireless networks. The mobility between nodes in a network is modeled by a stochastic mobility function which allows to change part of a network topology depending on an exponentially distributed delay and a network topology constraint. We allow continuous time stochastic behavior of processes running at network nodes, e.g. in order to be able to model randomized protocols. The introduction of group broadcast and an operator to help avoid flooding allows us to define a novel notion of broadcast abstraction. Finally, we define a weak bisimulation congruence and apply our theory on a leader election protocol

A Calculus for Mobile Ad-hoc Networks with Static Location Binding

AbstractWe present a process calculus for mobile ad hoc networks which is a natural continuation of our earlier work on the process calculus CMAN [J.C. Godskesen. A calculus for mobile ad hoc networks. In Proceedings of the 9th International Conference, COORDINATION 2007, volume 4467 of LNCS, pages 132–150, Paphos, Cyprus, June 2007. Springer–Verlag]. Essential to the new calculus is the novel restricted treatment of node mobility imposed by hiding of location names using a static binding operator, and we introduce the more general notion of unidirectional links instead of bidirectional links. We define a natural weak reduction semantics and a reduction congruence and prove our weak contextual bisimulation equivalence to be a sound and complete co-inductive characterization of the reduction congruence.The two changes to the calculus in [J.C. Godskesen. A calculus for mobile ad hoc networks. In Proceedings of the 9th International Conference, COORDINATION 2007, volume 4467 of LNCS, pages 132–150, Paphos, Cyprus, June 2007. Springer–Verlag] yields a much simpler bisimulation semantics, and importantly and in contrast to [J.C. Godskesen. A calculus for mobile ad hoc networks. In Proceedings of the 9th International Conference, COORDINATION 2007, volume 4467 of LNCS, pages 132–150, Paphos, Cyprus, June 2007. Springer–Verlag] we manage to provide a non-contextual weak bisimulation congruence facilitating ease of proofs and being strictly contained in the contextual bisimulation

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

AbstractWe 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