Detecting relay attacks in RFID systems using physical layer characteristics

Relay attacks are powerful attacks, since they are easy to set-up and can be performed with very limited resources. Furthermore this type of attack is very hard to detect. This paper proposes a novel approach to defend against amplify and forward relay attacks. The proposed scheme detects relaying attackers by measuring the noise statistic variations. Such information can be collected using the existing Radio-Frequency (RF) front-end equipments, without modifying the protocol and without additional hardware. A campaign of measurements using a contactless RFID system has been conducted to evaluate the effectiveness of the proposed method. The results show that this new scheme is practical and can be used to detect relay attacks.