The focus of this research was to study electronic payment systems and their security mechanism that can be achieved using cryptographic techniques. A number of electronic payment systems with a wide range of security characteristics have been previously proposed. The primary aim was to analyse security properties of those systems that have been implemented in a public domain or, are in the process of being implemented. My secondary emphasis has been to provide solutions to over come those weaknesses that might be present in those systems. The research also looked at generic payment architectures and provided a set generic security goals that formed the basis for analysis of security properties in electronic payment systems. The research consisted of analysis of prominent credit card payment systems like SET, Verified by Visa, MasterCard SecureCode, electronic cheque systems like FSTC eCheck protocol and a proposal for privacy enhanced electronic cheque system [JULY 2005] that overcomes weaknesses present in the existing system.