ENCRYPTED MEDIA KEY MANAGEMENT

摘要

A key or licence management system for the secure online distribution of digitized audio-visual works ("media") using encryption techniques. Encrypted media is stored on a media server while the encryption keys are stored on a media key server. Users acquire rights from online retailers to obtain from the media key server keys corresponding to the media they wish to play. The key server encrypts keys before releasing them, preferably with the user's public key using a public key encryption algorithm. Keys are stored in volatile memory at the user's client device and thus the user is in receipt of the key just in time to play the media.