Abstract: This paper presents an efficient RFID privacy-preserving authentication protocol (RPAP) based on public physically unclonable function (PPUF). RPAP is low cost as no extra computational ability other than a PPUF is required for each tag. Furthermore, RPAP has been proven to be strongly private due to the unpredictability and unclonability of PPUF: it can be resistant to almost all kinds of privacy related attacks such as corruption attacks. Finally, protocol RPAP is efficient and scalable thanks to the simulatability of PPUF.