US Patent 9152706 Anonymous identification tokens

Surveillance data is received from a source such as a traffic camera. The data is hashed and the signature is stored in a database. The data itself may be discarded after it is hashed. In an embodiment, extrinsic information such as time and location are associated with the signature. Identification data may be received and hashed. The signature belonging to the identification data may be compared to the database to determine if there is any matching surveillance data. If a match is found, the extrinsic information may be returned.