Reasoning about accountability in protocols for electronic commerce

Abstract

A new framework is proposed for the analysis of communication protocols that require accountability, such as those for electronic commerce. Informal arguments are presented to show that a heretofore un-explored property "provability" is pertinent to examine the potential use of communication protocols in the context of litigation, and in the context of audit. A set of postulates which are applicable to the analysis of proofs in general (e.g., zero knowledge proofs), and the proofs of accountability in particular, are proposed. The proposed approach is more natural for the analysis of accountability then the existing belief logics that have been used in the past for the analysis of key distribution protocols. Some recently proposed protocols for electronic commerce and public-key delegation are analyzed to illustrate the use of the new analysis framework in detecting (and suggesting remedies for eliminating) their lack of accountability, and in detecting and eliminating redundancies.>