NFC2FA
NFC2FA is a two-factor authentication system for NFC tags. It consists of firmware for a USB NFC controller and a driver which can interface with the controller to read and write encrypted data to and from an NFC tag. The controller was built using a Teensy++ 2.0 and a PN532.
License
Both the NFC2FA firmware and driver are licensed under the GNU General Public License, version 3. See COPYING for details.