摘要： ［1］D. E. Denning. Cryptography and Data Security. AddisonWesley Publishing Company, 1983 ［2］L. Olson,A. Marshall. Computer access Control Policy Choices. Computers ＆ Security,1990, 9(8) ［3］D. E. Bell. Lattices, Policies, and Implementations. In:Proc.13t