In this paper, we develop a security system which enhances the security of information during transmission over the World Wide Web for solving problems related to outflow of the information on the internet. Our system provides safe security functions without modifying the existing Web server and browser by utilizing CGI, Plug-in, and Socket Spy techniques. Our system implements user access control and data encryption/decryption by using the hardware cryptographic token instead of using a software technique as in previous systems, and hence is a more robust security system.