William M. Farmer Joshua D. Guttman Vipin Swarup Security for Mobile Agents: Authentication and State Appraisal. 118-130 1996 conf/esorics/1996 ESORICS http://dx.doi.org/10.1007/3-540-61770-1_31 db/conf/esorics/esorics1996.html#FarmerGS96