Patent ID: 7376624

Claim:
A method of distributing content items, the method comprising: obtaining encrypted content at a first entity, the encrypted content including a content item encrypted with a first encryption key; requesting, at the first entity, a first mutating identifier having a first part and a first key from an authenticator; encrypting, at the first entity, a watermark with the first key from the first mutating identifier to create a first encrypted label; grouping, at the first entity, the first part of the first mutating identifier with the first encrypted label to create a first encrypted watermark; receiving, at the first entity, a request for a content item from a second entity having an identity and a second mutating identifier over a communication link; generating a decryption key request at the first entity; transferring the decryption key request from the first entity to the authenticator over a communication link; receiving, at the first entity, the first decryption key and a second encryption key from the authenticator over a communication link; decrypting, at the first entity, the encrypted content with the first decryption key to obtain the content item; applying, at the first entity, the watermark to the content item to obtain watermarked content; encrypting, at the first entity, the watermarked content with the second encryption key to create encrypted watermarked content; transferring the first encrypted watermark from the first entity to the second entity over a communication link; verifying, at the authenticator, the identity of the second entity; based on verifying the identity of the second entity, sending the encrypted watermarked content from the first entity to the second entity over a communication link; and based on verifying the identity of the second entity, sending a second decryption key from the authenticator to the second entity over a communication link.