Abstract
This paper explores a type of non-repudiation protocol, called an anonymous and failure resilient fair-exchange e-commerce protocol, which guarantees a fair-exchange between two parties in an e-commerce environment. Models are formulated using the PEPA formalism to investigate the performance overheads introduced by the security properties and behaviour of the protocol. The PEPA eclipse plug-in is used to support the creation of the PEPA models for the security protocol and the automatic calculation of the performance measures identified for the protocol models.