Abstract. Radio Frequency Identification (RFID) systems are vulnerable to relay attacks (i.e., mafia, terrorist and distance frauds) when they are used for authentication purposes. Distance bounding protocols are particularly designed as a countermeasure against these attacks. These protocols aim to ensure that the tags are in a distant area by measuring the round-trip delays during a rapid challenge-response exchange of short authenticated messages. Terrorist fraud is the most challenging attack to avoid, because a legitimate user (a tag owner) collaborates with an attacker to defeat the authentication system. Many RFID distance bounding protocols have been proposed recently, with encouraging results. However, none of them provides the ideal security against the terrorist fraud. Motivated by this need, we first introduce a strong adversary model for Physically Unclonable Functions (PUFs) based authentication protocol in which the adversary has access to volatile memory of the tag. ...