SaaSRec+: a new context-aware recommendation method for SaaS services.

Cloud computing is an attractive model that provides users with a variety of services. Thus, the number of cloud services on the market is growing rapidly. Therefore, choosing the proper cloud service is an important challenge. Another major challenge is the availability of diverse cloud services with similar performance, which makes it difficult for users to choose the cloud service that suits their needs. Therefore, the existing service selection approaches is not able to solve the problem, and cloud service recommendation has become an essential and important need. In this paper, we present a new way for context-aware cloud service recommendation. Our proposed method seeks to solve the weakness in user clustering, which itself is due to reasons such as 1) lack of full use of contextual information such as cloud service placement, and 2) inaccurate method of determining the similarity of two vectors. The evaluation conducted by the WSDream dataset indicates a reduction in the cloud service recommendation process error rate. The volume of data used in the evaluation of this paper is 5 times that of the basic method. Also, according to the T-test, the service recommendation performance in the proposed method is significant.

Design of a Secure Authentication and Key Agreement Scheme Preserving User Privacy Usable in Telecare Medicine Information Systems.

Authentication and key agreement schemes play a very important role in enhancing the level of security of telecare medicine information systems (TMISs). Recently, Amin and Biswas demonstrated that the authentication scheme proposed by Giri et al. is vulnerable to off-line password guessing attacks and privileged insider attacks and also does not provide user anonymity. They also proposed an improved authentication scheme, claiming that it resists various security attacks. However, this paper demonstrates that Amin and Biswas's scheme is defenseless against off-line password guessing attacks and replay attacks and also does not provide perfect forward secrecy. This paper also shows that Giri et al.'s scheme not only suffers from the weaknesses pointed out by Amin and Biswas, but it also is vulnerable to replay attacks and does not provide perfect forward secrecy. Moreover, this paper proposes a novel authentication and key agreement scheme to overcome the mentioned weaknesses. Security and performance analyses show that the proposed scheme not only overcomes the mentioned security weaknesses, but also is more efficient than the previous schemes.