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The Mifare Classic is the most widely used contactless smartcard on the market.The stream cipher CRYPTO1 used by the Classic has recently been reverse engineered and serious attacks have been proposed. The most serious of them retrieves a secret key in under a second. In order to clone a card, previously proposed attacks require that the adversary either(More)
The mifare Classic is a contactless smart card that is used extensively in access control for office buildings, payment systems for public transport, and other applications. We reverse engineered the security mechanisms of this chip: the authentication protocol, the symmetric cipher, and the initialization mechanism. We describe several security(More)
Many approaches to deciding the satisfiability of quantifier-free formulae with respect to a background theory T—also known as Satisfiability Modulo Theory, or SMT(T)—rely on the integration between an enu-merator of truth assignments and a decision procedure for conjunction of literals in T. When the background theory T is the combination T 1 ∪ T 2 of two(More)
Recent improvements in propositional satisfiability techniques (SAT) made it possible to tackle successfully some hard real-world problems (e. g. , model-checking , circuit testing , propositional planning) by encoding into SAT. However , a purely Boolean representation is not expressive enough for many other real-world applications , including the(More)
The problem of deciding the satisfiability of a quantifier-free formula with respect to a background theory, also known as Satisfiability Modulo Theories (SMT), is gaining increasing relevance in verification: representation capabilities beyond propositional logic allow for a natural modeling of real-world problems (e.g., pipeline and RTL circuits(More)
This paper presents a novel technique for counterexample generation in probabilistic model checking of Markov Chains and Markov Decision Processes. (Finite) paths in counterexamples are grouped together in witnesses that are likely to provide similar debugging information to the user. We list five properties that witnesses should satisfy in order to be(More)