  To analyze strategic interactions arising in the cyber-security context, we
develop a new reputation game model in which an attacker can pretend to be a
normal user and a defender may have to announce attack detection at a certain
point of time without knowing whether he has been attacked. We show the
existence and uniqueness of sequential equilibrium in Markov strategies, and
explicitly characterize the players' equilibrium strategies. Using our model,
we suggest empirical and theoretical ways of calibrating the attack
probability, which is an important element of cyber-risks.
