Aniruddha Bohra Stephen Smaldone Liviu Iftode FRAC: Implementing Role-Based Access Control for Network File Systems. 95-104 2007 conf/nca/2007 NCA http://doi.ieeecomputersociety.org/10.1109/NCA.2007.25 db/conf/nca/nca2007.html#BohraSI07