Near Field Communication (NFC) enables fast and easy wireless communication between devices within the range of about 10 centimeters. The technology can be used for exchanging small amounts of data for payment systems or the configuration handling for other technologies like WiFi (Wireless Fidelity) or Bluetooth. NFC can also make use of a secure element to store sensitive data, it is an optimal technology platform for contact less electronic access and payment solutions. The secure element offers a dual interface, so that it can be accessed on one side through the base band of the handset and on the other side through the contact less interface of the NFC module. Besides storage capacity of an arbitrary amount of memory the secure element also comes with cryptographic functionality, which enables us to encrypt  transactions through the contact less interface or over the base band.

We show, how a mobile device can be used as a secure token to access buildings, parking lots or even serve as an event ticket. The secure token concept describes a method for secure generation and exchange of tokens within a system where secure transactions are not available and distributed verification is required.

As NFC is compatible to already existing systems like NXP's Mifare or Sony's Felica, the reader infrastructure does not need to be changed and so NFC can easily be integrated into already existing solutions. NFC devices that are capable of card emulation will definitely make mobile computing and commerce applications more convenient for the user and will help to save costs and time.