I declare that this assignment is all my own work and that I have acknowledged all quotations from the published or unpublished works of other people. I declare that I have also read the statements on plagiarism in Section 1 of the Regulations Governing Examination and Assessment Offences and in accordance with it I submit this project report as my own work. Abstract Our daily routine requires ...

Most approaches to formal protocol verification rely on an operational model based on traces of atomic actions. Modulo CSP, CCS, state-exploration, Higher Order Logic or strand spaces frills, authentication or secrecy are analyzed by looking at the existence or the absence of traces with a suitable property. We introduced an alternative operational approach based on parallel actions and an expl...

This paper aims to utilise different approaches to fair document exchange to propose a unified approach for the development of a flexible, general and secure fair document exchange system able to guarantee strong fairness for a document exchange among any number of parties under various situations. At the heart of this unified approach are methods for a verifiable and recoverable encryption of ...

Optimistic concurrency relies on speculative execution, read-write conflict detection, and checkpointrollback techniques to provide a programming model that replaces locks with the abstraction of atomic, isolated execution of critical sections. Previous research has shown that on chip multi-processors, a class of workloads featuring irregular parallelism and rare read-write conflicts can reap s...

In this paper, we present a fair-exchange electronic commerce (e-commerce) protocol, based on using an online trusted third party, that ensures fairness and prevents any party from gaining advantage by quitting prematurely from the transaction or otherwise misbehaving. An important contribution of this protocol is that the dispute resolution is taken care of within the protocol itself and does ...

We present new protocols for two parties to exchange documents with fairness, i.e., such that no party can gain an advantage by quitting prematurely or otherwise misbehaving. We use a third party that is L‘semi-trusted”, in the sense that it may misbehave on its own but will not conspire with either of the main parties. In our solutions, disruption by any one of the three parties will not allow...