Abstract: In various embodiments, transactions initiated by or on behalf of users between client systems and transaction systems are sent to authorization systems for approval. An authorization system contacts one or more registered devices for approval from a user of the registered devices for the transactions initiated by or on behalf of the users that are being handled by the transaction systems. A registered device sends an approval or denial based on user input. The authorization server then sends the approval or denial to a transaction system to complete a transaction.

Abstract: A method for generating a unique identity for objects having measurable properties. The teachings include deriving unique features of the object and using them to generate a fingerprint for the device. The teachings also include techniques for providing appropriate signal processing for the incoming information from any physical device to be fingerprinted. The invention also includes methods for access control to optical recording media and physical devices.