Strengthened public key protocol
CA 2176866 C · Owner: Vanstone, Scott A. · Inventors: Vanstone, Scott A.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A cryptosystem utilizes the properties of discrete logs in finite groups either in a public key message exchange or in a key exchange and generation protocol. If the group selected has subgroups of relatively small order the message may be exponentiated by a factor of the order of the group to place the message in a subgroup of relatively small order. To inhibit such substitution the base or generator of the cryptosystem is chosen to be a generator of a subgroup of prime order or a subgroup of an order having a number of relatively small divisors. The message may be exponentiated to each of the relatively small divisors and the result checked for the group identity. If the group identity is …
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 May 17, 1996 and granted February 12, 2013. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended May 17, 2016.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by May 17, 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.