Today content is distributed over the fixed Internet to portable devices such as mobile telephones and hand held devices. To prevent unauthorized copying etc., a digital rights management (DRM) scheme is used to protect the content. In the prior art, the content has been delivered in a session over a channel established between a computer, such as a content server, belonging the content provider or rights issuer, and a mobile device. The content is encrypted with a key and this key is sent to the mobile device separately and further encrypted with another key, which is associated with a mobile device. To form the encrypted key, the computer needs information from the mobile device, usually an identity number/public key and a random number. The content provider sends the encrypted key together with rights and permissions in a so called rights object. The mobile device will then be able to decrypt the content using information contained in the rights object.
One problem for a manufacturer of portable devices is that there is no established DRM standard. Open Mobile Alliance has put forth a standard for DRM targeted at download over the wireless network and peer-to-peer distribution using Obex and Bluetooth. The main problem with the OMA specification is that it does not cover the use of file-based DRM, e.g. using USB and memory cards. This effectively makes the specification useless for the case when a personal computer is connected to a content provider server for later delivery to the mobile device, or the case when the content is first downloaded to an external memory for later delivery to the mobile device.
USPTO Backgrounds
USPTO Backgrounds