A NEW GROUP KEY GENERATING MODEL FOR GROUP SHARING

In this paper, we are interested in those secure applications that have the one-to-many property, such as broadcasting secret messages from one source to many users on a network, accessing a sharable secure file by a subgroup of users in a data management system, etc. For these secure applications, Denning and Schneider [4] have proposed two methods to derive all of the group keys, one for each nonempty possible group. These methods require the cipher to be able to withstand the chosen-plaintext attack. In this paper, we propose a model to generalize their methods. Any cipher that is used on our proposed model to generate all of the group keys is only expected to be secure against the known-plaintext attack. Therefore, on the basis of our proposed model, we can have a more efficient method to generate the group keys.