A cryptographic solution to implement access control in a hierarchy and more
Indrakshi Ray, Indrajit Ray, Natu Narasimhamurthi · 2002
The need for access control in a hierarchy arises in several different contexts. One such context is managing the information of an organization where the users are divided into different security classes depending on who has access to what. Several cryptographic solutions have been proposed to address this problem --- the solutions are based on generating cryptographic keys for each security class such that the key for a lower level security class depends on the key for the security class that is higher up in the hierarchy. Most solutions use complex cryptographic techniques: integrating these into existing systems may not be trivial. Others have impractical requirement: if a user at a security level wants to access data at lower levels, then all intermediate nodes must be traversed. Moreover, if there is an access control policy that does not conform to the hierarchical structure, such policy cannot be handled by existing solutions. We propose a new solution that overcomes the above mentioned shortcomings. Our solution not only addresses the problem of access control in a hierarchy but also can be used for general cases. It is a scheme similar to the RSA cryptosystem and can be easily incorporated in existing systems.