An efficient key distribution scheme in cloud computing

Cloud computing is an emerging computing paradigm in which IT resources and capacities are provided as services over the Internet. It also brings forth new challenges for security when clients want to securely outsource the computation of operations to the untrusted cloud servers. In cloud computing, it is difficult to implement most of cryptographic protocols among clients for this reason that all clients are possibly weaker than computationally powerful players. Hence, clients have to appeal to cloud servers for assistance. However, cloud servers are untrusted so that cryptographic protocols cannot be realized securely. In this paper, we design a secure key agreement scheme for two weaker clients who delegate cloud server to compute modular exponentiation. In our scheme, two clients can get same key for symmetric cryptosystem even that cloud server is untrusted.