Cryptanalysis and improvement of a group RFID authentication protocol

In recent years, radio frequency identification (RFID) systems have become popular for identification. The key technology to protect the security of RFID systems is mutual authentication between the tags and the server. To enhance the efficiency of RFID systems, recently, Liu et al. proposed a group authentication protocol based on the concept of secret sharing. In this paper, we show that Liu et al.'s protocol falls short of providing security requirements. More specifically, we prove that in their protocol, authenticity of the tags to the server can not be achieved and on top of that the scheme can not be used more than once. We further propose a group mutual authentication protocol for RFID tags to overcome the mentioned drawbacks and prove that our proposal is secure. The results of analyzing the performance of the proposed protocol and its comparison with existing literature indicate that it outperforms current secure RFID authentication protocols.