On the Security of Rotation Operation Based Ultra-Lightweight Authentication Protocols for RFID Systems  
[PERSON]  
1 Computer Engineering Department, Shahid Rajaee Teacher Training University, Tehran 16788-15811, Iran; [EMAIL_ADDRESS]  
2 Electrical Engineering Department, Shahid Rajaee Teacher Training University, Tehran 16788-15811, Iran; [PERSON]DDRESS]  
3 School of Computer Science, Institute for Research in Fundamental Sciences (IPM), Tehran 19538-33511, Iran  
4 Correspondence: [PERSON]DDRESS], Tel. : +98-21-229-70117  
5 These authors contributed equally to this work. November 8, 2021 November 8, 20  
equipment that detect the presence of the tags in an environment and they retrieve the information stored in the tags. The back-end database which stores the extra information about the readers and the tags can be integrated with the reader in our cell phones or similar communication devices or on the separate server outside these devices. There are two important issues in the RFID systems: Identification and Authentication. Identification means that the reader or tag can identify each other. When the reader broadcasts the query signals to identify or search a special tag, it is possible more than one tag receives the reader's request and replies simultaneously, where their data collide on the reader side with each other and the collision occurs and data is destroyed. This is also the case for readers. If two or more requests arrive to a particular tag from two or more readers, the collision will occur and the data will be destroyed. So there are three kinds of collisions: The tag-tag collision, the reader-reader collision and the tag-reader collision. To counter this problem, anti-collision algorithms have been introduced which have their own literature, e.g., [1; 2; 3; 4; 5; 6; 7; 8; 9; 10; 11]. There are many issues in the field of anti-collision in RFID systems which researchers try to solve, e.g., increasing the number of read tags by the reader. Since the efficiency of RFID systems depends on the number of tags read at a specific time, much effort is being made to increase the number of tags that are read by the reader [5; 10; 11]. Once the tag or the reader has been successfully identified, in the next step it should be authenticated, in order to solve the RFID security issues. In this phase, which is known as the authentication phase of their communication, the rest of the readers and the tags in the vicinity are remaining-silent, to avoid collision. It should be noted in this paper that we assume the reader and the tag are using proper anti-collision protocol and our concentration is on the authentication phase of a reader to a tag communication. Authentication protocols are protocols that ensure that the parties involved in the protocol are the same as they claim, but the identification protocols do not provide that assurance. The authentication protocols can be one-way, that is, in the course of the process they are assured of one's identity, or they can be mutual, that is to say, they must ensure the identity of the parties during execution. **Problem Definition:** Assuming that a reader and a tag decided to communicate in the identification phase of their communication, to provide the security of RFID users, security protocols are also required. Security protocols, such as authentication protocols, are expected to provide the CIA triangle of security which is Confidentiality, Integrity, and Availability. Confidentiality means all of the secret information of protocols' parties must be kept secret. To contradict this property, secret disclosure attack and traceability attack were proposed. Integrity means the adversary cannot change and control protocol messages without the protocol parties' notice. Impersonation attacks can contradict integrity property. Availability means the protocols' parties can authenticate each other at any time and be synchronized with each other.