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.

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.

Reliability of the Cybex Reactor in the Assessment of an Agility Task

Two studies were performed to estimate the reliability of the Cybex Reactor in assessing agility tasks. In Study 1, participants (n=13) underwent identical testing sessions twice in 1 week. In Study 2, participants (n= 13) underwent identical testing sessions twice in 1 week, once 3 weeks later, and once 6 weeks later. Testing sessions consisted of four identical agility tasks requiring participants to react to cues shown on a video monitor. In Study 1, intraclass correlation coefficients (ICC) were .47 for Day 1 and .75 for Day 2 for time to complete each task. Participants performed faster on Day 2 (p <.05). In Study 2, ICC ranged from .58 to .83. ICC between sessions ranged from .59 to .73. Participants performed significantly faster each successive session except between Weeks 3 and 6 (p <.05). The Reactor appears to be reliable in assessing agility tasks with test–retest intervals of up to 6 weeks.