Physical access control
CA 2479869 C · Owner: Reyzin, Leo · Inventors: Libin, Phil; Engberg, David; Reyzin, Leo
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A system and method are disclosed for controlling physical access through a digital certificate validation process that works with standard certificate formats and that enables a certifying authority (CA) to prove the validity status of each certificate C at any time interval (e.g. every day hour, or , minute) starting with C's issue date D1. C's time granularity may be , specified within the certificate itself unless it is the same for all , certificates. For example all certificates may have a one-day granularity with each certificate expires 365 days after issuance. Given certain initial inputs provided by CA, a one-way hash function is utilized to compute values of a specified …
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 April 8, 2003 and granted July 9, 2013. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended April 8, 2023.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by April 8, 2025.
- 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.