Secret Computation with Secrets for Mobile Agent using One-time Proxy Signature

As an application for electronic commerce, a mobile agent is now used to search for special products or services and is executed for a specific job designated by a customer in the server's environment on behalf of a customer. On the way of performing its role, a mobile agent can be vulnerable to several cryptographic attacks. These attacks can be more serious when done by malicious servers. Among schemes to resolve this problem, the concept of encrypted function for secret computation was proposed in (ST97, KBC00). However, schemes that employ such encrypted functions enforce the server(host) to execute the functions of customer before verifying the mobile codes even in the case that the codes are maliciously modified. In this paper, we apply proxy signature scheme to the mobile agent system to enhance security and eciency. Also, we suggest one-time proxy signature scheme to limit the signing power of the server.