Crypographic key assignment scheme for access control in a hierarchy

@article{Chang1992CrypographicKA,
  title={Crypographic key assignment scheme for access control in a hierarchy},
  author={Chin-Chen Chang and Ren-Junn Hwang and Tzong-Chen Wu},
  journal={Inf. Syst.},
  year={1992},
  volume={17},
  pages={243-247}
}