The e20 off-line authentication device offers the ideal combination of security, simplicity, and functionality for determining and confirming a user’s identity in a virtual world. Using the security of a smart card, the e20 provides two-factor authentication for on-line banking applications, electronic transactions, and secure logical access to networks. The coupling of a smart card (“something I have”) and a PIN (Personal Identification Number, “something I know”) creates a strong authentication tool for any application where secure identification is required. The pocket-sized e20 authorizes users to manage their banking accounts at home or abroad, and provides non-repudiation for transactions. It can display the balance of an electronic purse or loyalty scheme. The e20 is completely platform independent and requires no connection to a PC or additional power supply. That makes it possible to work with any form of communication (PC, Phone, GSM), at any time and anywhere.