1 SITA: Protecting Internet Trade Agents from Malicious Hosts Qin Zhang & Mark Perry* Qin ZHANG (Department of Computer Science, University of Western Ontario, London, Ontario N6A 5B7) Mark PERRY (Assistant Professor, Department of Computer Science, University of Western Ontario, London, Ontario N6A 5B7, email: mperry@ uwo.ca Phone: 519 661 2111 x86644 Fax:519 661-3515 Web: http://www.csd.uwo.ca/markp/) (Corresponding author) Keywords: mobile agent security, electronic commerce, secret key encryption, public-key cryptography, digital signature, modeling agent security Abstract: The role of agents and their potential in the electronic marketplace has been discussed widely, but the issue of mobile agent vulnerability to attack, particularly from malicious hosts, needs further development. SITA is a framework that allows for multiple ‘window shopping’ agents to retrieve results for a user, as well as anonymity of that user, whilst providing a manageable key structure. This paper is concerned with a model improving the security of trade agents on the Internet and the provision of anonymous shopping agents.