Promising advances in the field of quantum computing indicate a growing threat to cryptographic protocols based on integer factorization. To counter this threat, researchers have already designed and tested alternative protocols that do not rely on factorization. Quantum key distribution, a cryptographic mechanism that relies on the inherent randomness of quantum mechanics, serves not only as a...

In this thesis we investigate methods for designing and analyzing cryptographic schemes which take into account the differences between humans and computers. On the one hand, humans have trouble performing complex algorithms and mathematical computations. On the other, humans live in a physical world, and can make use of " real " objects in ways that purely electronic algorithms cannot. Tamper-...

Given a cryptographic protocol, it is possible to extract an inference system modelling exactly the set of messages an active intruder can learn by manipulating this protocol. Unfortunately, there is no general proof-search procedure to test whether or not a term belongs to the theory of an inference system. This paper presents the preliminary results obtained during an attempt to circumvent th...

Many analysis techniques and decidability results have been obtained for cryptographic protocols. However all of them consider protocols with limited procedures for the processing of messages by agents or intruders: Information expected in a protocol message has to be located at a fixed position. However this is too restrictive for instance to model web-service protocols where messages are XML ...

The main contribution of this work is to provide solutions for component identification in composite technical systems such as automobiles or airplanes. We focused on the following three goals: (1) piracy protection to identify original parts and detect bogus parts; (2) system protection to monitor a system in order to ensure system integrity; and (3) theft protection to prevent the usage of st...

Steganography, the hiding of covert messages inside innocuous communication, is an active area of cryptographic research. Recent research has shown that provably undetectable steganography is possible in a wide variety of settings. We believe that the existence of such undetectable steganography will have far reaching implications. In this thesis, we investigate the impact of steganography on t...

We study the veri cation of secrecy and authenticity properties for cryptographic protocols which rely on symmetric shared keys. The veri cation can be reduced to check whether a certain parallel program which models the protocol and the speci cation can reach an erroneous state while interacting with the environment. Assuming nite principals, we present a simple decision procedure for the reac...

Call by contract is a way to specify and use interchangeable services in secure protocols, so that protocols and services can be independently designed and verified. A selection algorithm is given to test whether a candidate service is uniformly selectable. To facilitate independent security verification of the calling protocol and its services, contracts and requests also provide an NDA (Non-D...