Since Zhang and Malik’s work in 2003 [ZM03], it is well-known that modern DPLL-based SAT solvers with learning can be instrumented to write a trace on disk from which, if the input is unsatisfiable, a resolution proof can be extracted (and checked), and hence also an unsatisfiable core: a (frequently small) unsatisfiable subset of the input clauses. In this article we first give a new algorithm...

We present a practical tool for defining and proving properties of recursive functions in the Coq proof assistant. The tool Defining and Reasoning About Recursive Functions 115 A more general solution consists in defining functions by well-founded recursion. Two approaches prevail in the current state-of-the-art: the so-called accessibility predicate approach [21] (and its variant converging it...

We have developed a practical algorithm for state-machine replication [7, 11] that tolerates Byzantine faults. The algorithm is described in [4]. It offers a strong safety property — it implements a linearizable [5] object such that all operations invoked on the object execute atomically despite Byzantine failures and concurrency. Unlike previous algorithms [11, 10, 6], ours works correctly in ...

Practical formal veriication of complex computer systems requires proof robustness and eeciency to protect against inevitable mistakes and system spec-iication and design changes. PVS is a theorem-proving system based on higher-order logic with which we demonstrate the kind of robust code proofs needed for veriication of realistic-sized computing systems.

We construct a new group signature scheme using bilinear groups. The group signature scheme is practical, both keys and group signatures consist of a constant number of group elements, and the scheme permits dynamic enrollment of new members. The scheme satisfies strong security requirements, in particular providing protection against key exposures and not relying on random oracles in the secur...

A formal proof of convergence of a class of algorithms for reducing inconsistency of pairwise comparisons (PC) method is presented. The design of such algorithms is proposed. The convergence of the algorithms justifies making an inference that iterated modifications of the pc matrix made by human experts should also converge. This is instrumental for credibility of practical applications of the...

We reexamine the problem of Multiple Description coding considered last week. We briefly review the import concepts and results. An overview of the basic methods of proof are provided. We further formulate this problem in the context of distributed source coding and from this framework examine a practical coding scheme for the symmetric problem provided by Pradhan et. al.

We present an approach to generalization of practical Identity-Based Encryption scheme of [BF01]. In particular we show how the protocol could be used on finite modular lattices and as a special case on vector spaces over finite field. The original proof of security for this protocol does not hold in this general algebraic structure, thus this is still a work in progress.

We identify a fragment of Presburger arithmetic enriched with free function symbols and cardinality constraints for interpreted sets, which is amenable to automated analysis. We establish decidability and complexity results for such a fragment and we implement our algorithms. The experiments run in discharging proof obligations coming from invariant checking and bounded model-checking benchmark...

This paper presents the experience of a real deployment of Calamari, an ad-hoc localization system for sensor networks. It provides a practical evaluation of many ideas from the literature, serving as a proof-of-concept in some cases and revealing tacit assumptions or unexpected problems in others.