A DYNAMIC ACCESS-CONTROL SCHEME BASED UPON THE KNAPSACK-PROBLEM

A new dynamic access control scheme for information protection systems is proposed in this paper. The main idea of it is inspired by the concept of the trapdoor knapsack problem proposed by Merkle and Hellman. Since the knapsack problem is an NP-complete problem, the security of access control is achieved henceforth. Our scheme associates each user with some user keys and each file with some file keys. There is a positive integer set of S'; through a simple formula on keys and S', the corresponding access privilege can be easily revealed in the protection system. Moreover, by employing our scheme, insertion or deletion of the user/file can be processed effectively with only a few previously defined keys and locks required to be modified.