Controlling access in large partially ordered hierarchies using cryptographic keys.

Min-Shiang Hwang Wei-Pang Yang Controlling access in large partially ordered hierarchies using cryptographic keys. 99-107 2003 67 Journal of Systems and Software 2 http://dx.doi.org/10.1016/S0164-1212(02)00091-2 db/journals/jss/jss67.html#HwangY03