The security and improvement of an ultra‐lightweight RFID authentication protocol

It is very challenging on designing cryptographically strong security functions that can be incorporated into low‐cost radio frequency identification (RFID) tags. Some RFID authentication protocols were proposed using only ultra‐lightweight primitives, while the security of them must be scrutinized before being put forth into any real application. In this paper, we present two effective attacks, namelyde‐synchronization attackandfull‐disclosure attack, against an efficient ultra‐lightweight RFID mutual authentication protocol: LMAP 2 , which is recently proposed by Peris‐Lopezet al. These active attacks are so serious as they cannot only disable the authentication capability of an RFID tag by destroying synchronization between the tag and the RFID reader, but also disclose all secret values stored in the tag. We point out the design flaws of the protocol and based on that, we improve the protocol with a stateful variant (SLMAP). The improved protocol is more secure in sense of tag anonymity, man‐in‐the‐middle (MITM) resistance, and forgery prevention as shown in our analysis, and is more compact due to reduced operations and memory usage on implementing such a tag.