In this paper, a novel lightweight authentication protocol for RFID systems is proposed. The protocol is based on a non-linear feedback shift register sequences generated by the position digit algebra function, which has a large average period lengths. This function uses only the radix
additions (for some
≥ 2), which makes it very efficient from a computational point of view, and suitable enough to be implemented in the RFID tags’ logic. The protocol appears to have good privacy and security properties.