Design redundant in the user registration phase Sample Clauses

Design redundant in the user registration phase. In order to avoid the impersonation attack in Xxxx xx al.’s[13] protocol, the authors compute BSm = h (PSIDm SIDm y), which indicates the identity SIDm and pseudoidentity PSIDm of Sm are bundled up with the secret key y of CS by hash function. As proved in the section of security analysis in [14], this technique can be effective against the cloud server impersonation attack. Similarly, the authors claim that the operation ∆i = h (PIDi IDi x) is aslo used to avoid that the user cheats CS with a false identity. Unfortunately, we further research discover that this design is redundant in the user registration phase. AS described in [11], the authentication scheme using smart card is mainly to resolve the problem, which the remote servers must store a verification table con- taining user identities and passwords. In the login phase of Xxxx et al.’s [14] pro- tocol, only legal Ui with the real identity IDi, password Pi and biometric Bi can access the card reader. Moreover, the operation PIDi = h (IDi bi) makes clear that pseudoidentity PIDi is also bound to the real identity IDi by hash function during the subsequent login phase, and the value bi is protected in the smart card. So, if Ui can login into the card reader, the control server CS can authenticate Ui. That’s why the smart card is used in this authentication protocol. Therefore, the operation ∆i = h (PIDi IDi x) is designed redundant in Amin et al.’s protocol. The detailed description will be presented in the section 4.2.