Information processing system and method
CA 2372510 A1 · Owner: Sony Corporation · Inventors: Ishiguro, Ryuji; Oishi, Tateo; Osawa, Yoshitomo
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
An effective key block (EKB) used for key distribution structure of tree structure is re-structured to a simplified two-branch or multi-branch tree in which a decodable end node or leaf is at the lowest layer so as to create a restructured layered tree according to only a key corresponding to the node or leaf of the re-structured layered tree. A tag as identification data about the tree position of an encryption key stored in the EKB is stored. In the tag not only the position identification but data for judging if encryption key data is present in the EKB is stored. The amount of data in the EKB is greatly reduced and the decoding by a device is simplified. Thus providing an , …
Read the whole patent
Listed from its CIPO record in Patent Yard's archive of Canadian patents past their term. Its claims, description and drawings are in the CIPO record and on Google Patents, and the Claude kit works from them.
Why it's free to use
- Filed April 4, 2001. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended April 4, 2021.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by April 4, 2023.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
Timeline
Timeline From CIPO dates
Sources & verification
Official CIPO records
Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.