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EP0265180A2 Expired / Lapsed EP ⏱️ 0.0 years remaining

Multiplier in a galois field

Assignee: Panasonic Holdings Corp
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Filing: 1987-10-15
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Granted: —
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Expires: 2007-10-15
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Abstract

Abstract A circuit effects regular multiplication of two field elements in a Galois field GF(2<m>). Each of the field elements is expressed by an m-bit binary member. The two field elements are applied to a binary multiplier array which generates (2m - 1)-bit partial prodcuts. The partial products are divided by a generator polynomial of the Galois field to produce final m-bit binary products.

Inventors

  • 👤 Michihiro Matsumoto
  • 👤 Kazuhiro Murase

Bibliographic Details

Application Number —
Jurisdiction EP
Data Source google_patents
Last Synchronized 2026-11-02 08:30
CPC Classifications
G; G06; G06F; G06F7/00; G06F7/38; G06F7/48; G06F7/52; H; H03; H03M; H03M13/00; H03M13/03; H03M13/05; H03M13/13; H03M13/15; H03M13/151; G06F7/60; G06F7/72; G06F7/724; H03M13/033

Claims Analysis

Total Claims: 6
Claim 1
Independent Claim 153 words
An apparatus for carrying out multiplication of field elements P = Σp i •a', Q = Σq i • a' (i = 0 through m - 1) in a Galois field GF(2 m ) whose generator polynomial is g(x) = x m + Σk i •x' (i = 0 through m - 1) comprising: a binary multiplier array supplied with the field elements P, Q for generating partial products R = Σr n •α n (n = 0 through 2m - 2) where r n = Ep u• q v for all n = u + v (u = 0 through m - 1 < n and v = 0 through m - 1 < n); and a polynomial reducer supplied with the partial products R for generating final products S = Σs i •α' (i = 0 through m - 1) through division of the partial products R by the generator polynomial.
Claim 2
Independent Claim 153 words
An apparatus for carrying out multiplication of field elements P = Σp i •a', Q = Σq i • a' (i = 0 through m - 1) in a Galois field GF(2 m ) whose generator polynomial is g(x) = x m + Σk i •x' (i = 0 through m - 1) comprising: a binary multiplier array supplied with the field elements P, Q for generating partial products R = Σr n •α n (n = 0 through 2m - 2) where r n = Ep u• q v for all n = u + v (u = 0 through m - 1 < n and v = 0 through m - 1 < n); and a polynomial reducer supplied with the partial products R for generating final products S = Σs i •α' (i = 0 through m - 1) through division of the partial products R by the generator polynomial.
Claim 3
Dependent Claim 38 words
An apparatus according to claim 1, wherein said binary multiplier array comprises AND gates each for effecting an AND operation of p i •q i and exclusive-OR gates for effecting bit addition of outputs from said AND gates.
Claim 4
Dependent Claim 61 words
An apparatus according to claim 1, wherein said polynomial reducer comprises a plurality of exclusive-OR gates for developing terms of α 2m-2 through α m of the partial products R to terms of α m- ' through a O thereof and effecting bit addition of the developed terms and the terms of α m-1 through a° of the partial products R.
Claim 5
Dependent Claim 71 words
An apparatus according to claim 1, wherein said polynomial reducer comprises a plurality of exclusive-OR gates arranged for developing each term α n of the partial products R to terms of α n-1 through α n-m thereof in repeated cycles from n = 2m - 2 to m, thereby developing terms of α 2m-2 through α m of the partial products R to terms of α m-1 through α 0 thereof.
Claim 6
Dependent Claim 36 words
An apparatus according to claim 4, wherein said polynomial reducer further includes AND gates connected so that one input of each of the AND gates is controlled by a coefficient k i of the generator polynomial.

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