Patent Yard Sign in
Expired Canadian patentCanada

Stream cipher design with revolving buffers

CA 2497935 C · Owner: Venkatesan, Ramarathnam · Inventors: Venkatesan, Ramarathnam; Mironov, Ilya

CIPO record

Overview

Drawings and full text

Its claims, description and drawings are in the Canadian Patents Database.

Open the CIPO record

Abstract From the Canadian patent

Techniques are disclosed to limit short-term correlations associated with outputs of stream cipher keystream generators. Output values of a generator are paired such that the paired outputs are sufficiently far apart to be considered independent. In one described implementation a method includes sequentially storing a plurality of results provided by a stream cipher output rule in a first second, and third storage units. A pairing function pairs individual values from the first and third storage units that are at least a threshold value apart. Upon reaching the threshold value of the output rule results the contents of the first, second, and third storage units are rotated serially.

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 February 22, 2005 and granted November 27, 2012. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended February 22, 2025.
  • Certificates of supplementary protection extend only drug patents, and it isn't classified as one.
  • We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
FiledFebruary 22, 2005
GrantedNovember 27, 2012
Term endedFebruary 22, 2025
Patent numberCA 2497935 C
Classification (IPC)H04L9/18

Timeline

Timeline From CIPO dates

2006200820102012201420162018202020222024Application filedFeb 22, 2005Patent grantedNov 27, 2012Term endedFeb 22, 2025

Sources & verification

Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.