Patent ID: 8185476

Claim:
A Digital Rights Management (“DRM”) system operable to protect consumer privacy, the system comprising: a client DRM module of a client operable to communicate with a license server; a packaged digital content including an encrypted portion and a plain text header, the plain text header including a key identifier uniquely related to a key usable for decrypting the encrypted portion, the key identifier extractable from the packaged digital content by the client DRM module; and a processor operable to execute the client DRM module; wherein the client DRM module is further operable to: blind the key identifier; send the blinded key identifier to the license server, wherein the blinded key identifier is signed by the license server; receive a license including the signed blinded key identifier from the license server, un-blind the signed blinded key identifier resulting in the key, the key being a stable signature, usable to decrypt the encrypted portion, and wherein the key identifier is not obtained by the license server from the client DRM module.