Non-monotonic transformation of access rights

It is known that monotonic transformations unify a number of diverse access control mechanisms such as amplification, copy flags, separation of duties, and synergistic authorization. The importance and expressive power of nonmonotonic transformations is demonstrated. A formal model, called nonmonotonic transform (NMT), is defined. A distributed implementation of NMT is proposed using a client-server architecture. The implementation is remarkably simple and modular in concept. It is based on access control lists and allows for efficient and immediate revocation which could be partial, complete, selective, temporary, or permanent