Digital signature algorithm
CA 2111572 C · Owner: United States Government As Represented By The Secretary Of Commerce National Institute Of Standards And Tech · Inventors: Kravitz, David William
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A method is provided for generating and verifying a digital signature of a message m. This method requires a pair of corresponding public and secret keys (y and x) for each signer as well as a pair of public and secret values (r and k) generated for each message by the signer. The public value r is calculated according to the rule r = (g k mod p) mod q. A value s is then selected according to the rule s = k-1(H(m) + xr) mod q where H is a known conventional hashing function. The message m along, with the signature (r, s) is then transmitted. When the transmitted signal is received a verification process is provided. The received values of r and s are tested to determine whether they are …
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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 July 24, 1992 and granted January 5, 1999. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended July 24, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by July 24, 2014.
- 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.