Time until Adversary’s Success

The most general time-based metric measures the time until the adversary’s success. It assumes that the adversary will succeed eventually, and is therefore an example of a pessimistic metric. This metric relies on a definition of success, and varies depending on how success is defined in a scenario. For example, success in a communication system can be if the adversary identifies n out of N of the target’s possible communication partners. Success can also be when the adversary first compromises a communication path. In an onion routing system such as Tor, path compromise happens when the adversary controls all relays on a user’s onion routing path.