Abstract: A digital rights management (DRM) system for distribution of digital content such as audio or video uses a token passing scheme to enhance security of the content from unauthorized access and use, including access by unauthorized players. The token is requested from the central content or DRM server by a host device such as a user's computer, using security related information. The token is then passed to a media player associated with the host device, the token being encrypted using a key special to that particular player. Upon receipt of the token, the player transmits back to the server certain related security information confirming receipt of the token and in return receives keys for decryption of the associated digital content. In the absence of proper passing of the token, player access to the content, or further access to other content, is denied. This also allows the player to communicate directly with the server for obtaining the keys.

Abstract: For digital rights management (DRM) of e.g. digitally delivered music or video, a technique to make the decryption keys more secure. The technique fragments a message (song or video or other) into a number of portions, and uses a different decryption key for each portion. Each of the various keys is a function of the preceding key, in one version. In another version, each key is a function of a seed value and of the particular portion of the material with which the key is associated.

Abstract: For digital rights management (DRM) of e.g. digitally delivered music or video, a technique to make the decryption keys more secure. The technique fragments a message (song or video or other) into a number of portions, and uses a different decryption key for each portion. Each of the various keys is a function of the preceding key, in one version. In another version, each key is a function of a seed value and of the particular portion of the material with which the key is associated.

Abstract: A digital rights management (DRM) system for distribution of digital content such as audio or video uses a token passing scheme to enhance security of the content from unauthorized access and use, including access by unauthorized players. The token is requested from the central content or DRM server by a host device such as a user's computer, using security related information. The token is then passed to a media player associated with the host device, the token being encrypted using a key special to that particular player. Upon receipt of the token, the player transmits back to the server certain related security information confirming receipt of the token and in return receives keys for decryption of the associated digital content. In the absence of proper passing of the token, player access to the content, or further access to other content, is denied. This also allows the player to communicate directly with the server for obtaining the keys.