Using a secret key to foil an eavesdropper

This work addresses secrecy with distributed systems in mind. We consider an adversary who wishes to attack a system and find the optimal communication and use of secret key to share information in such a system. Instead of measuring secrecy by “equivocation,” we define a value function for the system, based on the actions of the system and the adversary, and set out to design a system that maximizes the average value obtained against the worst adversary.