On two RFID privacy notions and their relations

• Main Authors: LI, Yingjiu, DENG, Robert H., LAI, Junzuo, MA, Changshe
• Format: text
• Language: English
• Published: Institutional Knowledge at Singapore Management University 2011
• Subjects: RFID; privacy; pseudorandom function; Information Security
• Online Access: https://ink.library.smu.edu.sg/sis_research/1472; https://ink.library.smu.edu.sg/context/sis_research/article/2471/viewcontent/Two_RFID_Privacy_2011_afv.pdf
• Institution: Singapore Management University

Privacy of RFID systems is receiving increasing attention in the RFID community. Basically, there are two kinds of RFID privacy notions in the literature: one based on the indistinguishability of two tags, denoted as ind-privacy, and the other based on the unpredictability of the output of an RFID protocol, denoted as unp*-privacy. In this article, we first revisit the existing unpredictability-based RFID privacy models and point out their limitations. We then propose a new RFID privacy model, denoted as unp*-privacy, based on the indistinguishability of a real tag and a virtual tag. We formally clarify its relationship with the ind-privacy model. It is proven that ind-privacy is weaker than unp*-privacy. Moreover, the minimal (necessary and sufficient) condition on RFID tags to achieve unp-privacy is determined. It is shown that if an RFID system is unp*-private, then the computational power of an RFID tag can be used to construct a pseudorandom function family provided that the RFID system is complete and sound. On the other hand, if each tag is able to compute a pseudorandom function, then the tags can be used to construct an RFID system with unp*-privacy. In this sense, a pseudorandom function family is the minimal requirement on an RFID tag’s computational power for enforcing RFID system privacy. Finally, a new RFID mutual authentication protocol is proposed to satisfy the minimal requirement.