Current security systems typically rely on the adversary's computational limitations (e.g., the fact that it cannot invert a hash function or perform large-integer factorization). Wireless networks offer the opportunity for a different, complementary kind of security, which relies not on the adversary's computational limitations, but on its limited network presence (i.e., that the adversary cannot be located at many different points in the network at the same time). We take a first step toward designing and building a wireless security system that leverages this opportunity: We consider the problem where a group of n nodes, connected to the same broadcast wireless network, want to agree on a shared secret (e.g., an encryption key), in the presence of an adversary Eve who tries to listen in and steal the secret. We propose a secret-agreement protocol, where the n nodes of the group keep exchanging bits until they have all agreed on a bit sequence that Eve cannot reconstruct (with very high probability). We provide experimental evidence-to the best of our knowledge, the first one-that a group of wireless nodes can generate thousands of new shared secret bits per second, with their secrecy being independent of the adversary's computational capabilities.

Abstract-We present a method for the translation of a discretetime fragment of Simulink into the synchronous subset of the BIP language.The translation is fully compositional, that is, it preserves completely the original structure and reveals the minimal control coordination structure needed to perform the correct computation within Simulink models. Additionally, this translation can be seen as providing an alternative operational semantics of Simulink models using BIP. The advantages are twofold. It allows for integration of Simulink models within heterogeneous BIP designs. It enables the use of validation and automatic implementation techniques already available for BIP on Simulink models.The translation is currently implemented in the Simulink2BIP tool. We report several experiments, in particular, we show that the executable code generated from BIP models has comparable runtime performances as the code produced by the Real-Time Workshop on several Simulink models.

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Abstract-We consider the problem where a group of wireless nodes, connected to the same broadcast domain, want to create pairwise secrets, in the presence of an adversary Eve, who tries to listen in and steal these secrets. Existing solutions assume that Eve cannot perform certain computations (e.g., largeinteger factorization) in useful time. We ask the question: can we solve this problem without assuming anything about Eve's computational capabilities?We propose a simple secret-agreement protocol, where the wireless nodes keep exchanging bits until they have agreed on pairwise secrets that Eve cannot reconstruct with very high probability. Our protocol relies on Eve's limited network presence (the fact that she cannot be located at an arbitrary number of points in the network at the same time), but assumes nothing about her computational capabilities. We formally show that, under standard theoretical assumptions, our protocol is information-theoretically secure (it leaks zero information to Eve about the secrets). Using a small wireless testbed of smartphones, we provide experimental evidence that it is feasible for 5 nodes to create thousands of secret bits per second, with their secrecy being independent from the adversary's capabilities.