Implementation of a Countermeasure to Relay Attacks for Contactless HF Systems

Nowadays, HF contactless technologies following the ISO 14443 standard are extensively used worldwide. Critical applications like access control or payment require high security guaran‐ tees. However, contactless channels are less secure and offer more opportunities for any kind of intrusion than other ways of communication; e.g. eavesdropping and contactless card activation using false reader [1, 2, 3, 11]. Among the attacks on the physical layer, relay attack is the most dangerous because of its simplicity, its impact and its insensitivity to cryptographic protections. It consists in setting up an unauthorized communication between two devices out of their operating range [4, 6]. On Figure 1, two attackers are able to create a link between the reader and the contactless card without the agreement of the owner. A relay is composed of two elements: a first one close to the reader and called proxy, a second one close to the card and called mole. These two elements communicate together by a wired or a wireless link