Patent · US Expired

Cyphering/decyphering performed by an integrated circuit

US7403620B2 · kind B2 · utility

15Cited by
0References
7Claims
0Family size

Assignee

Inventors

Key dates

Filing dateJul 1, 2003
Grant dateJul 22, 2008
Priority date
Expiry dateMar 21, 2025

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH04L2209/08
  • WIPO fieldDigital communication
  • WIPO sectorElectrical engineering

Abstract

A method of cyphering and/or decyphering, by an integrated circuit, of a digital input code by means of several keys, comprising: dividing the code into several data blocks of same dimensions; and applying to said blocks several turns of a cyphering or decyphering comprising submitting each block to at least one same non-linear transformation and of subsequently combining each block with a different key at each turn, the operands being masked, upon execution of the method, by at least one first random number having the size of the code and all the blocks of which have the same value by combining, by an XOR-type function, the input and output blocks of the non-linear transformation with said random number.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.