On Refresh-Based Tag Identification Schemes

We give a definition for a tag identification scheme which uses refresh techniques. We also define a notion of privacy for such a scheme, which accurately reflects real-world threats and tag capabilities. Universal re-encryption, as a refresh technique, has been proposed as an approach to enhance privacy in a pervasive computing environment. However, it permits a hidden adversarial communication channel in a tag identification scheme. Insubvertible encryption was subsequently introduced to address this limitation. We show how the security properties of these two encryption techniques can be used to help enhance privacy in a refresh-based tag identification scheme, and discuss their limitations. We also suggest the practical use of refresh approaches in RFID applications.