In his PhD thesis, Keeping fairness alive. Design and format verification of optimistic fair exchange protocols, Mohammad Torabi Dashti studied two aspects: the design and the verification of optimistic 'fair exchange protocols'.
The first part of his research deals with a new certified e-mail protocol in which person X can send an e-mail to person Y in exchange for a receipt. With the 'fair exchange protocol' person Y will only receive the e-mail if person X will receive the receipt. Such an exchange is only possible when there is a trustworthy third party involved. The strength of the protocol lies in the use of keychains. Less storage is needed to ensure the 'fairness'.
In the second part of his research Dashti focuses on 'intruder modelling' which contain thorough 'fairness' restrictions. In this way it becomes possible to verify the liveness aspects of optimistic fair exchange protocols. The developed intruder model shows similarities with the intruder model of Dolev-Yoa, except for the part in which every e-mail must reach its destiny. Such trustworthy communication networks are crucial in most optimistic fair exchange protocols. To proof the empiric effectiveness of Dashti's intruder model he analysed protocols for electronic payments and digital rights.
The research has been carried out at CWI and was financed by NWO. Dashti will receive his PhD on 27 February 2008 at the Vrije Universiteit Amsterdam. The announcement in Dutch can be found at the science guide of the Vrije Universiteit Amsterdam.
