The rapidly increased availability of always-on broadband telecommunication environments and lower-cost vital signs monitoring devices bring the advantages of telemedicine directly into the patient's home. Hence, the control of access to remote medical servers' resources has become a crucial challenge. A secure authentication scheme between the medical server and remote users is therefore needed to safeguard data integrity, confidentiality and to ensure availability. Recently, many authentication schemes that use low-cost mobile devices have been proposed to meet these requirements. In contrast to previous schemes, Khan et al. proposed a dynamic ID-based remote user authentication scheme that reduces computational complexity and includes features such as a provision for the revocation of lost or stolen smart cards and a time expiry check for the authentication process. However, Khan et al.'s scheme has some security drawbacks. To remedy theses, this study proposes an enhanced authentication scheme that overcomes the weaknesses inherent in Khan et al.'s scheme and demonstrated this scheme is more secure and robust for use in a telecare medical information system.

No abstract

An authenticated encryption scheme provides a mechanism of signing and encrypting simultaneously, and furthermore, the receiver can verify and decrypt the signature at the same time. Tseng et al. proposed two efficiently authenticated encryption schemes which can check the validity of the sent data before message recovery, but in fact their schemes cannot achieve completely the function. In this article, we point out the flaw and propose an improved scheme of revision.

No abstract

No abstract