An identity verification system receives context signals from an authenticating computing device in response to a target user requesting access to a secure asset. The identity verification system identifies candidate locations for the operational context assigned to historical context signals labeled as being measured at a known location and compares the context signal to each historical signal to determine a location of the operational context corresponding to the received context signal. The identity verification system determines a match probability for the target user based on a risk score assigned to the location of the operational received context signal and grants the requesting target user access to the secured asset in response to determining that the match probability is greater than the operational security threshold.