In 1989, Brewer and Nash (BN) proposed the Chinese Wall Security Policy (CWSP). Intuitively speaking, they want to build a family of impenetrable walls, called Chinese walls, among the datasets of competing companies so that no datasets that are in conflict can be stored in the same side of Chinese walls. Technically, the idea is: (X, Y) Ï CIR (= the binary relation of conflict of interests) if and only if (X, Y) Ï CIF (= the binary relation of information flows). Unfortunately, BN’s original proof has a major flaw (Lin, 1989). In this chapter, we have established and generalized the idea using an emerging technology, granular computing.