| The research project presented in this thesis analyses various aspects of the new digital economy in the context of secure data transfer and digital transaction handling over open communication networks. Specifically, our work deals with several monetary and transactional issues related to the general concept of electronic commerce, and in particular, to the notion of electronic transactions over the Internet.; Different approaches are shown in a comprehensive survey of digital payment systems for Internet-based electronic commerce. A set of evaluation and analysis criteria, both internal and external to a particular system, is used to analyze system representatives of each class. Based on this analysis, a list of needs and requirements for a flexible new system is determined. We introduce the general notion of generic «transfer of value», achieved by using digital envelopes. In this context, we propose a new transactional concept based on a digital envelope transfer protocol (DTEP), used for transport, transfer and exchange of value, irrespective of what they actually might represent. In this manner, electronic transactions become substantially more flexible. Based on this protocol, a new system, named TRANZIX, allows different types of electronic documents or other digital valuables to be transported and exchanged concurrently using the same support.; The system provides a very high level of security, protecting data contained in its digital envelopes through public-key-based encryption. Encryption is also used to limit and control accessibility to the system, while user authentication and data integrity are secured using digital signatures. Authentication is complemented by additional biometric protection based on handwritten signatures, which also ensures non-repudiation.; TRANZIX offers a short collection delay for e-shops and its digital bills provide reasonable anonymity that could accommodate both individuals and governments. The system is also symmetric, both buyers and vendors can use the same software-only virtual wallet to transact, transport or transfer any digitizable object having a non-intrinsic value, including, in particular, money.; While other systems employ digital cash to achieve funds transfer, TRANZIX uses digital bills to complement the payload as payment for the service. Virtual cash is therefore only one among many different kinds of e-documents that can take advantage of this transactional system. Several targeted applications are presented, including the controlled access to physical resources on an intranet using tokenized micropayments, as well as the customized retailing of virtual objects and other digital resources on the Web. (Abstract shortened by UMI.)... |
