Apparatus for avoiding complementarity in an encryption algorithm
CA 2136287 C · Owner: General Instrument Corporation Of Delaware · Inventors: Sprunk, Eric
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
An implementation of a security algorithm such as DES is provided that overcomes the complementarity weaknesses provided by conventional implementations. In a DES implementation a cryptographic processor applies the DES algorithm to a data block. The DES processor includes a first input port for receiving the data block a second input port for receiving a cryptographic key and an output port for outputting the data block after encryption. A nonlinear function that does not have complementarity is applied to at least one of the ports. The nonlinear function can comprise a lookup table which could be advantageously derived from a DES S-Box.
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 November 21, 1994 and granted April 2, 2002. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended November 21, 2014.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by November 21, 2016.
- 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.