Computer-aided verification provides effective means of analyzing the security of cryptographic primitives. However, it has remained a challenge to achieve fully automated analyses yielding guarantees that hold against computational (rather than symbolic) attacks. This paper meets this challenge for public-key encryption schemes built from trapdoor permutations and hash functions. Using a novel combination of techniques from computational and symbolic cryptography, we present proof systems for analyzing the chosen-plaintext and chosen-ciphertext security of such schemes in the random oracle model. Building on these proof systems, we develop a toolset that bundles together fully automated proof and attack finding algorithms. We use this toolset to build a comprehensive database of encryption schemes that records attacks against insecure schemes, and proofs with concrete bounds for secure ones.

SUMMARY Noninterference is a strong security policy that enforces confidentiality and integrity. Many solutions are proposed in the state of the art for verifying this policy in programs, but few tools are proposed to implement it. In this paper, we define a high‐level model called Component Information Flow, and we develop the tools that simplify distributed secure system development and deployment. The developer focuses on developing the functional part of his or her system and defines his or her system security properties by using a high‐level configuration. When this configuration is validated, that is, no security leak is detected, the system security code is generated. To validate and demonstrate the effectiveness of our approach, we apply the Component Information Flow tools to a classical Web service use case. Copyright © 2012 John Wiley & Sons, Ltd.

Hash functions are the swiss army knife of cryptographers. They are used to generate unique identifiers in hash-and-sign signatures, as one-way functions for one-time-password, to break the structure of the input in key derivation functions and also for authentications. We propose a formal analysis of domain extenders for hash functions in the in differentiability framework. We define a general model for domain extenders and provide a unified proof of their security in the form of a generic reduction theorem. Our general model captures many iterated constructions such as domain extenders, modes of operation of symmetric cryptography such as CBC-MAC or block ciphers based on Feistel networks. Its proof has been carried out using the Computational Indistinguishability Logic of Barthe et al.. The theorem can help designers of hash functions justifying the security of their constructions: they only need to bound the probability of well-defined events. Our model allows to consider many SHA-3 finalists and is instantiated on two well-known constructions, namely Chop-MD and Sponge. Finally, the in differentiability bounds which we prove are convincing since they match previous proofs and the application of our result on the sponge construction (underlying the Keccak design) highlights the lack of an additional term in the bound provided by Bertoni et al., as was anticipated but not justified by Bresson et al..

Privacy is one of the main issues in electronic voting. We propose a family of symbolic privacy notions that allows to assess the level of privacy ensured by a voting protocol. Our definitions are applicable to protocols featuring multiple votes per voter and special attack scenarios such as vote-copying or forced abstention. Finally we employ our definitions on several existing voting protocols to show that our model allows to compare different types of protocols based on different techniques, and is suitable for automated verification using existing tools.

Computational Indistinguishability Logic (CIL) is a logic for reasoning about cryptographic primitives in computational models. It captures reasoning patterns that are common in provable security, such as simulations and reductions. CIL is sound for the standard model, but also supports reasoning in the random oracle and other idealized models.

In this paper we study the reachability problem for parametric flat counter automata, in relation with the satisfiability problem of three fragments of integer arithmetic. The equivalence between non-parametric flat counter automata and Presburger arithmetic has been established previously by Comon and Jurski. We simplify their proof by introducing finite state automata defined over alphabets of a special kind of graphs (zigzags). This framework allows one to express also the reachability problem for parametric automata with one control loop as the satisfiability of a 1-parametric linear Diophantine systems. The latter problem is shown to be decidable, using a number-theoretic argument. In general, the reachability problem for parametric flat counter automata with more than one loops is shown to be undecidable, by reduction from Hilbert's Tenth Problem. Finally, we study the relation between flat counter automata, integer arithmetic, and another important class of computational devices, namely the 2-way reversal bounded counter machines.

Chosen-ciphertext security is by now a standard security property for asymmetric encryption. Many generic constructions for building secure cryptosystems from primitives with lower level of security have been proposed. Providing security proofs has also become standard practice. There is, however, a lack of automated verification procedures that analyze such cryptosystems and provide security proofs. This paper presents an automated procedure for analyzing generic asymmetric encryption schemes in the random oracle model. It has been applied to several examples of encryption schemes among which the construction of Bellare-Rogaway 1993, of Pointcheval at PKC'2000 and REACT.

The design of embedded real-time systems requires skills from multiple specific disciplines, including, but not limited to, control, computer science, and electronics. This often involves experts from differing backgrounds, who do not recognize that they address similar, if not identical, issues from complementary angles. Design methodologies are lacking in rigor and discipline so that demonstrating correctness of an embedded design, if at all possible, is a very expensive proposition that may delay significantly the introduction of a critical product. While the economic importance of embedded systems is widely acknowledged, academia has not paid enough attention to the education of a community of high-quality embedded system designers, an obvious difficulty being the need of interdisciplinarity in a period where specialization has been the target of most education systems. This paper presents the reflections that took place in the European Network of Excellence Artist leading us to propose principles and structured contents for building curricula on embedded software and systems.

Pioneering work has been done by Jonkers [18] to define a semantics of pointer manipulating programs that is abstract in the sense of ignoring low-level aspects such as dangling pointers and garbage objects. We explore the principles of such storeless semantics from a logical point of view, first defining a simple logic to completely characterize heap structures up to isomorphism. Second, we extend this language to a full-blown alias logic (AL) that allows to express regular properties of unbounded heap structures. Along the development, we present an operational storeless semantics and give sound and complete total correctness axioms for deterministic programs in the form of Hoare triples, using AL.