A Formal Model for Parameterized Role-Based Access Control. - Ali E. Abdallah; Etienne J. Khayat (Formal Aspects in Security and Trust, 2004)

Risk Based Security Analysis of Permissions in RBAC. - Nimal Nissanke; Etienne J. Khayat (WOSIS, 2004)

Formal Z Specifications of Several Flat Role-Based Access Control Models. - Ali E. Abdallah; Etienne J. Khayat (SEW, 2006)

Role-based access control (RBAC) : formal modelling and risk-based administration. - Etienne J. Khayat (2006)