14. Implementing a Quantum Solution to Database Hierarchy Control

Data access control in a hierarchy is currently a complex structure. Different groups need access to sets of data, some of which overlap, while the rest of the data remains secret. Managers and directors need to access the data that is hidden from regular users. To manage this, users are organized into partially ordered sets, or posets. Nodes in the posets represent users with the same access rights. Current solutions use independent keys to access sections of data. This is chaotic, particularly for upper users in the hierarchy. A proposed solution is up-down computable keys, as described by Nagy and Akl in 2010 [1]. The downfall of this solution is that it is only applicable to stable posets. Users leaving and entering the organization at arbitrary levels or even moving within the structure, may invalidate multiple keys or even all the keys in a poset. Nagy and Akl [1] propose a quantum mechanical solution; by managing systems with two keys per user, a quantum and a classical key, the database is able to use computable keys that the user has no access to. Instead of direct access to the key, the system uses the quantum and the classical keys to compute the access key. The purpose of the study is to design a physical system to implement quantum key database access, able to accommodate large businesses and governments with large, fluctuating and complex organizational hierarchies. Such a system would also be highly secure, suitable for databases with sensitive data. References [1] N. Nagy and S. G. Akl, “A quantum cryptographic solution to the problem of access control in a hierarchy,” Parallel Processing Letters, vol. 20, no. 3, pp. 251–261, 2010.