Cryptographic apparatus with double feedforward hash function
CA 2179691 C · Owner: General Instrument Holdings, Inc. · Inventors: Anderson, Candace; Sprunk, Eric; Moroney, Paul
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Apparatus is provided for authenticating information using a double feedforward hash function to provide complementarity in the implementation of an encryption algorithm. A cryptographic processor has a first input for receiving plaintext a second input for receiving a key and an output for outputting ciphertext generated by cryptographically processing the plaintext and key. A first circuit element is responsive to the ciphertext and plaintext for outputting a first ciphertext derivative. A second circuit element is responsive to at least a portion of the first ciphertext derivative and the key for outputting a second ciphertext derivative. The first and second circuit elements can be XOR …
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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 June 21, 1996 and granted December 19, 2000. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended June 21, 2016.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by June 21, 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
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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.