Two rounds RFID grouping-proof protocol

In this paper, we focus on a particular RFID application called a grouping-proof, where an entity such as an RFID reader generates a proof that two or more tags have been scanned simultaneously. This proof is then verified by the server, which processes the tags' data in the system. However, designing a grouping-proof protocol is challenging for two reasons. Firstly, in some cases, the server that authenticates the tags is offline during the scanning process, thus the tags' data need to be assembled in a valid grouping-proof to be authenticated later. Secondly, a number of recent grouping-proof protocols are either prone to attacks, or they are not efficient in terms of performance. In this paper, we present an offline two rounds grouping-proof protocol that provides immunity against well-known attacks on RFID protocols and improves tag's memory and computing performance. We analysed our protocol using a mechanical formal analysis tool called Scyther, which did not find any feasible attack(s). Finally, an implementation of the proposed protocol is conducted to measure the tag's memory space and computing time cost using an IAIK UHF RFID tag emulator.