  We propose a technique to assess the vulnerability of the power system state
estimator. We aim at identifying measurements that have a high potential of
being the target of false data injection attacks. From an adversary's point of
view, such measurements have to show the following characteristics: i) being
influential on the variable estimates, and ii) corrupting their measured values
is likely to be undetected. Additionally, such characteristics should not
change significantly with the system's operating condition. Our technique
provides a systematic way of identifying measurements with such
characteristics. We illustrate our methodology on a 4-bus system and the New
England 39-bus system.
