Cryptographic protocols are constantly exposed to new attack methods. When some cryptographic protocol gets exposed there is a need to replace it. This is hard because most cryptographic protocols are hard coded in applications. Applications should implement a way of negotiating cryptographic protocols used. In that way old and vulnerable protocols could be easily replaced with new ones. The ag...

Cryptographic protocols are useful for trust engineering in distributed transactions. Transactions require specific degrees of confidentiality and agreement between the principals engaging in it. Moreover, trust management assertions may be attached to protocol actions, constraining the behavior of a principal to be compatible with its own trust policy. We embody these ideas in a cryptographic ...

ii iii Preface In this course, we focus on asymmetric techniques for cryptographic protocols, also considering proofs of security for various constructions. Motivating example: 'Sinterklaaslootjes trekken' is a Dutch tradition for buying presents and writing little poems, see, The same tradition is also known as " Secret Santa " , and a lot of websites and programs are available to help people ...

This paper presents a new method for specifying and analyzing cryptographic protocols. Our method o ers several advantages over previous approaches. Our technique is the rst to allow reasoning about nonmonotonic protocols. These protocols are needed for systems that rely on the deletion of information. There is no idealization step in specifying protocols; we specify at a level that is close to...

A transformation F between protocols associates the messages sent and received by participants in a protocol Π1 with messages sent and received in some Π2. Transformations are useful for modeling protocol design, protocol composition, and the services that protocols provide. A protocol transformation determines a map from partial behaviors A1 of Π1—which we call “skeletons”—to skeletons F (A1) ...

Messages in cryptographic protocols are made up of a small set of elements; keys, nonces, timestamps, and names, amongst others. These elements must possess specific properties to be useful for their intended purpose. Some of these properties are prescribed as part of the protocol specification, while others are assumed to be inherited from the execution environment. We focus on this latter cat...

1 : x||y String x is concatenated with string y. 2 : λ(C) Distribution of a given instance or random variable C. 3 : D(X, Y) Statistical distance between the distributions of the two random variables X and Y. 6 : = Stat Statistical indistinguishability between two Random Variables: see Definition 8. 7 : = Comp Computational indistinguishability between two Random Variables: see Definition 9. 8 ...