关键词: 射频识别, 随机数, 双向认证, 按位运算, 二次剩余定理

Abstract: In the RFID system, the tag and the reader communicate wirelessly, which is easily attacked by the attacker to intercept the relevant private information. In order to ensure the communication security between the both, a bidirectional authentication protocol based on the quadratic residue theorem is proposed. The protocol uses the quadratic residue theorem to encrypt the transmitted data and it is based on the complex problem of factoring large number, so the protocol can ensure the security of the data effectively. Furthermore, random numbers are mixed into the encryption process, which makes the messages different each time so as to increase the difficulty of cracking. Besides, the use of ultra-lightweight bitwise operation, to a certain extent, can reduce the overall system computing and cost. In addition, the database introduces the check mechanism for random numbers to enable the system to resist attacks such as desynchronization attack. Security analysis shows that the security of this protocol is higher than other same kind of classical protocols which can guarantee the reliability of data transmission. Performance analysis shows that the protocol has less computational complexity and lower cost than other same kind of classical protocols.

Key words: Radio Frequency Identification（RFID）, random numbers, bidirectional authentication, bitwise operation, quadratic residual theorem