Lightweight RFID Authentication Protocols for Special Schemes

This thesis addresses the problem of providing secure protocols for the practical application of low cost Radio-Frequency Identification (RFID) tags. This is particularly challenging because the tags are limited in cryptographic functionality and general performance, but also when there is a need to read multiple tags in a range of practical environments whilst maintaining data privacy. Several protocols exist for reading of RFID tags, either individually or within a group; however some have design weaknesses and/or would be impractical for a real-world implementation. The contribution of this work is first to review and propose improvements to the security of existing protocols for single tags and then to groups of tags. It then goes on to propose optimised protocols, exploiting capabilities that are common in real RFID tag systems, but are overlooked in most theoretical protocols. For the reading of individual tags, reference is made to the HB family of RFID protocols and in particular the lightweight HB-MP protocol. This thesis contributes analysis revealing that the protocol is vulnerable to man-in-the-middle attacks and then goes on to propose an improved version HB-MP. For multi-tag group reading an analysis is performed of protocols based on the yoking proof mechanism proposed by A. Juels, identifying problems with tag ordering and data privacy. This leads to original proposals for improved protocols offering tag order independence, privacy, select-response optimisations, binary tree anti-collision groupings and simultaneous tag authentication via bit collision processing. .