Abstract: An RFID tag may execute instructions from an authenticated RFID reader. A tag determines a handle and a first parameter, both of which may be random numbers, and sends the handle to a reader. Upon receiving a challenge from the reader, the tag determines and sends a cryptographic response to the challenge based on an algorithm, a tag key, the first parameter, and the challenge. Upon receiving a message with a second parameter and a tag instruction, the tag executes the tag instruction upon verifying that the second parameter derives from the first parameter and the tag handle.

Abstract: An RFID tag may execute instructions from an authenticated RFID reader. A tag determines a handle and a first parameter, both of which may be random numbers, and sends the handle to a reader. Upon receiving a challenge from the reader, the tag determines and sends a cryptographic response to the challenge based on an algorithm, a tag key, the first parameter, and the challenge. Upon receiving a message with a second parameter and a tag instruction, the tag executes the tag instruction upon verifying that the second parameter derives from the first parameter and the tag handle.

Abstract: Encrypted data objects are distributed via a broadcast communication channel or media. Relatively large access indicia may also be pre-distributed to any potential data object users and/or purchasers via an access communication channel or media. Subsequently, when a particular potential user or purchaser wishes to decrypt a given data object, he or she communicates to a data distribution point the identity of the desired data object and the identity of a valid access incidium. A relatively short decryption key is then furnished via a key distribution communication channel or media to permit decryption while at the same time permitting appropriate accounting operations to take place. The system is resistant to abuse in several ways but in part because such abuse would be approximately as difficult as would be re-distribution of the entire decrypted data object itself.