Tuesdays the PTO issues new patents. Both of today's Spotlight Patents concern aspects of digital watermarking. Assigned to Panasonic (JP), the first patent addresses a content distribution system that may use watermarks. Assigned to AT&T, the second patent addresses techniques for detecting distribution of multimedia content.
8,601,590, "Content distribution system," assigned to Panasonic (JP).
A content distribution system for transferring contents between transmission device and reception device. The transmission device includes: key obtaining unit that obtains, from reception device, public keys and public key identifiers; watermark embedding unit that embeds a different public key identifier, as electronic watermark, into each of contents that are identical in substance; an encryption unit that encrypts contents using public keys to generate encrypted contents; and transmission unit that transmits encrypted contents to reception device. The reception device includes: key storage unit storing public keys, public key identifiers, and a private key that makes a pair with one of the public keys; key transmission unit that transmits public keys and public key identifiers to the transmission device; content receiving unit that receives encrypted contents from transmission device; and decryption unit that obtains a content from the received encrypted contents, using the private key.
8,601,503, "Detecting distribution of multimedia content," assigned to AT&T.
A system and method is disclosed for detecting distribution of multimedia content. The volume level of data traffic is monitored for a plurality of users to select any users with high-bandwidth usage. The time of day and the day of the week may be considered when determining whether a user is a high-bandwidth user. Upon selecting a user as one with high-bandwidth usage, such user may be subject to packet inspections of data traffic streams. In some embodiments, content identification parameters or watermarks are added to one or more packets in a data traffic stream carrying multimedia content.