| Digital multimedia content is delivered to homes via the Internet, satellite, terrestrial and cable networks. Scrambling is a common approach used by conditional access systems to prevent unauthorized access to audio/visual data. The descrambling keys are securely distributed to the receivers in the same transmission channel. Their protection is an important part of the key management problem...

The notion of “sending a secret message to the future” has been around for over a decade. Despite this, no solution to this problem is in common use, or even attained widespread acceptance as a fundamental cryptographic primitive. We name, construct and specify an implementation for this new cryptographic primitive, “Time-Lapse Cryptography”, with which a sender can encrypt a message so that it...