Reducing Time Complexity in RFID Systems

Radio frequency identification systems based on low-cost computing devices is the new plaything that every company would like to adopt. Its goal can be either to improve the productivity or to strengthen the security. Specific identification protocols based on symmetric challengeresponse have been developed in order to assure the privacy of the device bearers. Although these protocols fit the devices’ constraints, they always suffer from a large time complexity. Existing protocols require O(n) cryptographic operations to identify one device among n. Molnar and Wagner suggested a method to reduce this complexity to O(log n). We show that their technique could degrade the privacy if the attacker has the possibility to tamper with at least one device. Because low-cost devices are not tamper-resistant, such an attack could be feasible. We give a detailed analysis of their protocol and evaluate the threat. Next, we extend an approach based on time-memory trade-offs whose goal is to ...

• Type: Conference
• Year: 2005
• Where: SACRYPT
• Authors: Gildas Avoine, Etienne Dysli, Philippe Oechslin
• Keywords: Low-cost Computing Devices, SACRYPT 2005, Specific Identification Protocols, Time Complexity