An Efficient Key Management Scheme for Access Control in a User Hierarchy

In a user hierarchy, a user belongs to higher-privileged class will have access right to message owned by user in a lower-privileged class; while the opposite in not allowed. Many schemes based on cryptography have been proposed to solve this problem. However, previous schemes need large values associated with each security class. Considering the solution of dynamic access problem in a hierarchy, a novel scheme based on the difficulty of factoring a produce of two large primes, Chinese remainder theorem and one-way hash function is proposed to manage the cryptographic keys in the paper. The scheme attempts to achieve two goals. One is to reduce the space needed to store public parameters. The other is to achieve both efficiency and on-iteration in deriving the successorpsilas secret keys.