Many researchers believe electronic wallets (secure storage devices that maintain account balances) are the solution to electronic commerce challenges. This paper argues for a more powerful model --- a secure coprocessor --- that can run a small operating system, run application programs, and also keep secure storage for cryptographic keys and balance information. We have built a system called Dyad, on top of a port of the Mach 3.0 microkernel to the IBM Citadel secure coprocessor. This paper describes the abstract architecture of Dyad and a general discussion of secure coprocessor implementations of a variety of electronic commerce applications: ffl Copy protection for software ffl Electronic cash (including a critique of proposed solutions for point-of-sale electronic wallet systems) ffl Electronic contracts ffl Secure postage 1 Introduction Many researchers believe electronic wallets (secure storage devices that maintain account balances) are the solution to electronic commerc...

The large-scale reuse and distribution of software components requires communities of software developers supported by an infrastructure of communication and information services. This paper elaborates on the notion of software communities and describes their role in software production. Problems associated with sharing components within a software community are discussed. Finally the paper describes the steps needed to promote the establishment of a robust software community. 1. Overview In this paper we propose an approach to software development that is based on the cooperative exchange and large-scale reuse of software components. Our hypothesis is that the successful dissemination of software tools and components presupposes a well organized community of developers who are ready to share ideas, methods, tools and code. Furthermore these communities must be supported by software information systems which manage collections of reusable components. In the following sections we disc...