We address the proof-based development of cryptographic protocols satisfying security properties. Communication channels are supposed to be unsafe. Analysing cryptographic protocols requires precise modelling of the attacker’s knowledge. In this paper we use the event B modelling language to model the knowledge of the attacker for a class of cryptographic protocols called cascade protocols. The...

Context. Cryptographic protocols are distributed programs which use cryptographic primitives to secure communication over untrusted networks (such as the Internet). They are designed to achieve security properties such as confidentiality, authentication or anonymity. Due to the complexity of cryptographic primitives, the inherent concurrency and the untrusted nature of networks, their design ha...

In the last two decades, Internet brought a new dimension to communications. It is now possible to communicate with anyone, anywhere at anytime in few seconds. While some distributed communications, like e-mail, chat, . . . , are rather informal and require no security at all, others, like military or medical information exchange, electronic-commerce, . . . , are highly formal and require a qui...

Governments and international standards bodies have established certification procedures for security-critical technologies, such as cryptographic algorithms. Such standards have not yet been established for cryptographic protocols and hence it is difficult for users of these protocols to know whether they are trustworthy. This is a serious problem as many protocols proposed in the past have fa...

Cryptographic protocols form the backbone of our digital society. Unfortunately, the security of numerous critical components has been neglected. As a consequence, attacks have resulted in financial loss, violations of personal privacy, and threats to democracy. This thesis aids the secure design of cryptographic protocols and facilitates the evaluation of existing schemes. Developing a secure ...

Symbolic analysis of cryptographic protocols is dramatically simpler than full-fledged cryptographic analysis. In particular, it is readily amenable to automation. However, symbolic analysis does not a priori carry any cryptographic soundness guarantees. Following recent work on cryptographically sound symbolic analysis, we demonstrate how Dolev-Yao style symbolic analysis can be used to assert...

Cryptographic protocols are designed to provide security services, such as key distribution, authentication and non-repudiation, over insecure networks. The design process of cryptographic protocols is highly complex. In particular, the translation from the informal protocol description to the formal protocol specification is an error-prone step, as the exact meaning of the requirements of the ...

Symbolic analysis of cryptographic protocols is dramatically simpler than full-fledged cryptographic analysis. In particular, it is simple enough to be automated. However, symbolic analysis does not, by itself, provide any cryptographic soundness guarantees. Following recent work on cryptographically sound symbolic analysis, we demonstrate how Dolev-Yao style symbolic analysis can be used to as...