As a guest user you are not logged in or recognized by your IP address. You have
access to the Front Matter, Abstracts, Author Index, Subject Index and the full
text of Open Access publications.
Owing to the individual privacy, system security and resource limitation of low-cost RF tag, ultralightweight RFID authentication has been massively investigated in these years. Recently, Kianersi et al. [3] and Lee et al. [4] proposed two well-studied RFID authentication schemes which attempt to achieve data confidentiality and tag computation efficiency. However, these two protocols are vulnerable as the shared secrets can be out of synchronization via a series of challenge-response operations. In this paper, we demonstrate the detailed malicious procedures on these two mechanisms and show their vulnerabilities.