Encryption apparatus and method capable of controlling encryption process in accordance with an internal state
CA 2173688 C · Owner: Shimizu, Hideo · Inventors: Kawamura, Shinichi; Shimizu, Hideo
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
An encryption apparatus is constituted by a plurality of rungs of round functions. Each round function comprises internal state storing means for storing an internal state, internal state updating means for updating the internal state stored in the storing means, and an F-function for executing an encryption upon receipt of data to be encrypted an, encryption key, and the internal state stored in the internal state storing means. The internal state stored in the internal state storing means is updated by the internal state updating means every time the encryption is executed by the F-function.
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 9, 1996 and granted January 18, 2000. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended April 9, 2016.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by April 9, 2018.
- 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.