Untraceable electronic cash
CA 2229206 C · Owner: Microsoft Technology Licensing, Llc · Inventors: Simon, Daniel R.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
An electronic cash protocol including the steps of using a one-way function f1(x) to generate an image f1(x1) from a preimage x1; sending the image f1(x1) in an unblinded form to a second party; and receiving from the second party a note including a digital signature, wherein the note represents a commitment by the second party to credit a predetermined amount of money to a first presenter of the preimage x1 to the second party.
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 August 29, 1996 and granted July 15, 2003. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended August 29, 2016.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by August 29, 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.