An Improved Lightweight RFID Authentication Protocol

This study extends the vulnerability analysis of a RFID authentication protocol and offers solutions to security weaknesses through enhanced measures. Vajda and Buttyan (VB) proposed a lightweight RFID authentication protocol, called XOR. Defend, Fu, and Juels (DFJ) analyzed it and proposed repeated keys and nibble attacks to the protocol. In this paper, we identify the source of vulnerability within VB’s original successive session key permutation algorithm. We propose three improvements, namely removing bad shuffles, hopping the runs, and authenticating mutually, to prevent DFJ’s attacks, thereby significantly strengthening the security of the protocol without introducing extra resource cost.