How to Turn a GSM SIM into a Web Server

Abstract

We describe the WebSIM, an approach that integrates GSM SIMs into the Internet. The underlying idea is to implement a Web Server inside a SIM, and to allow for transparent access to it from the Internet. The contribution of our approach is that a SIM, which is currently a security module (smart card) fitted in a GSM mobile phone, becomes also a personal security server in the Internet. Like any other server in the Internet, it speaks TCP/IP and processes HTTP requests, e.g. for accessing certain SIM services (e.g. authentication) via CGI scripts. The Internet connectivity of a SIM inside a mobile phone can be achieved by having a proxy host tunnel IP packets to the SIM over SMS.