Regression verification is an approach complementing regression testing with formal verification. The goal is to formally prove that two versions of a program behave either equally or differently in a precisely specified way. In this paper, we present a novel automatic approach for regression verification that reduces the equivalence of two related imperative integer programs to Horn constraints over uninterpreted predicates. Subsequently, state-of-the-art SMT solvers are used to solve the constraints. We have implemented the approach, and our experiments show non-trivial integer programs that can now be proved equivalent without further user input.

Abstract. We, the organizers and participants, report our experiences from the 1st Verified Software Competition, held in August 2010 in Edinburgh at the VSTTE 2010 conference.

Abstract. Quantitative information flow analysis (QIF) is a portfolio of security techniques quantifying the flow of confidential information to public ports. In this paper, we advance the state of the art in QIF for imperative programs. We present both an abstract formulation of the analysis in terms of verification condition generation, logical projection and model counting, and an efficient concrete implementation targeting ANSI C programs. The implementation combines various novel and existing SAT-based tools for bounded model checking, # SAT solving in presence of projection, and SAT preprocessing. We evaluate the technique on synthetic and semi-realistic benchmarks.

Abstract. This paper reports on the experiences with the program verification competition held during the FoVeOOS conference in October 2011. There were 6 teams participating in this competition. We discuss the three different challenges that were posed and the solutions developed by the teams. We conclude with a discussion about the value of such competitions and lessons that can be learned from them.

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