Accountability as Fundamental property for Electronic Commerce Protocols

Accountability in electronic commerce (e-commerce) protocols is concerned with the ability to show that particular parties who engage in the protocols are responsible for some transactions. Traditionally, it is used only for resolving payment disputes amongst parties. In this thesis, we argue that the accountability is not just a property for resolving disputes but a fundamental and critical property for analyzing e-commerce protocols. In particular, we show a novel use of the accountability in that it can be used to specify and analyze many goals of e-commerce protocols. The general goal of e-commerce protocols is to ensure engaging parties that they have authorizations to perform transactions relevant to them. Some specific goals of the protocols include client privacy property and each party’s requirement on authorizations for payment transaction. Furthermore, we show that the accountability can be used to resolve an additional kind of disputes also, namely disputes on goods. In order to demonstrate the novel use of the accountability, we develop a logic which extends existing logics for the accountability. We show the practical