This book constitutes the refereed proceedings of the International Conference on Trends in Electronic Commerce, TREC'98, held in Hamburg, Germany, in June 1998. The book presents 19 revised full papers selected from a total of 75 submissions. While focussing mainly on technological issues, the book also takes into account important social, administrative, regulatory, and legal aspects. The papers are organized in sections on business over the Internet, security and payment, middleware and brokerage, interorganisational workflow management, and agent technology.