Randomized hashing for tag Identification in RFID networks

In this paper we approach the problem of identifying a set of objects in an RFID system. We propose a new query protocol based on an hashing mechanism. All tags compute a simple random function whose result range is set by the reader. Then, the reader queries all possible values in the chosen range, and tags answer with their ID when the output of the random hash function, applied to their ID, equals the number queried by the reader. Collisions may occur. In such a case, a new round of queries, with a different range, is performed. Simulation results show that our method performs better than the proposed query protocols, in terms of number of queries, which is a measure strictly related to delay.