The Internet, especially the World Wide Web, is moving from a free, academic domain to a profitable commercial world. This underscores the importance of a digitally secure means of electronic payment for an electronic commerce application. The payment is usually an important part of an electronic commerce transaction, and it deals with the transfer of trust, either as cryptographically signed promises, or as digital cash, between the customer, the merchant, and the payment service provider. Due to the explosive growth of e-commerce transactions, many electronic modes of payment are devised to address a diverse set of Internet user requirements (Guida, Stahl, Bunt et al., 2004; Tsiakis & Sthephanides, 2005; Garfinkel, 2003; Usher, 2003; Polk, Hastings, & Malpani, 2003; Evans & Yen, 2005; Marchesini, Smith, & Zhao, 2005; Lancaster, Yen, & Huang, 2003; Lekkas, 2003; Medvinsky & Neuman, 1995; Schoenmakers, 1997; Levi & Koc, 2001; Mahony, Peirce, & Tewari, 2001; DigiCash Press, 1994; Neuman & Tso, 1994; Vivtek, 2000). The background of this article is that we have developed a mobile agent-based restaurant reservation and ordering system whereby users are able to search for restaurants that fulfill a list of user-entered parameters (e.g., type of cuisines, ambiance, specialties such as steaks, etc.) (Quah & Leow, 2003). The system is built on the IBM Aglet mobile agent platform. (A mobile agent is a small executable code/program that can migrate itself to remote hosts and execute predefined instructions—e.g., information retrieval, and return the processed information to its originating host system) (Lanage & Oshima, 1998). Due to the uniqueness of our system, we find the existing e-commerce payment methods inadequate to fit our system’s need. As such, we studied several existing methods and adapted one into our system operation structure. The use of mobile agent to implement the payment system adds robustness and scalability to the system.