Secure Personal Computing in an Insecure Network
A method for implementing secure personal computing in a network
with one or more central facilities is proposed.  The method employs a
public-key encryption device and hardware keys.  Each user is responsible 
for his own security and need not rely on the security of
the central facility or the communication links.  A user can safely
store confidential files in the central facility or transmit confidential 
data to other users on the network. 
CACM August, 1979
Denning, D.E.
