Security Improvement of an RFID Security Protocol of ISO/IEC WD 29167-6

The use of radio frequency identification (RFID) has become widespread in a range of applications. International standards of RFID technology are actively being developed for securing RFID communications. Recently, ISO/IEC WD 29167-6 proposed three security protocols, namely Protocol 1, 2 and 3. In this letter, we show that Protocol 1 - mutual authentication and secure communication in security mode - is vulnerable to a man-in-the-middle attack. We also propose a countermeasure against the attack.