Extended Euclidean algorithm

In arithmetic and computer programming, the extended Euclidean algorithm is an extension to the Euclidean algorithm, and computes, in addition to the greatest common divisor (gcd) of integers a and b, also the coefficients of Bézout's identity, which are integers x and y such that This is a certifying algorithm, because the gcd is the only number that can simultaneously satisfy this equation and divide the inputs.It allows one to compute also, with almost no extra cost, the quotients of a and b by their greatest common divisor.

Comment
enIn arithmetic and computer programming, the extended Euclidean algorithm is an extension to the Euclidean algorithm, and computes, in addition to the greatest common divisor (gcd) of integers a and b, also the coefficients of Bézout's identity, which are integers x and y such that This is a certifying algorithm, because the gcd is the only number that can simultaneously satisfy this equation and divide the inputs.It allows one to compute also, with almost no extra cost, the quotients of a and b by their greatest common divisor.
Has abstract
enIn arithmetic and computer programming, the extended Euclidean algorithm is an extension to the Euclidean algorithm, and computes, in addition to the greatest common divisor (gcd) of integers a and b, also the coefficients of Bézout's identity, which are integers x and y such that This is a certifying algorithm, because the gcd is the only number that can simultaneously satisfy this equation and divide the inputs.It allows one to compute also, with almost no extra cost, the quotients of a and b by their greatest common divisor. Extended Euclidean algorithm also refers to a very similar algorithm for computing the polynomial greatest common divisor and the coefficients of Bézout's identity of two univariate polynomials. The extended Euclidean algorithm is particularly useful when a and b are coprime. With that provision, x is the modular multiplicative inverse of a modulo b, and y is the modular multiplicative inverse of b modulo a. Similarly, the polynomial extended Euclidean algorithm allows one to compute the multiplicative inverse in algebraic field extensions and, in particular in finite fields of non prime order. It follows that both extended Euclidean algorithms are widely used in cryptography. In particular, the computation of the modular multiplicative inverse is an essential step in the derivation of key-pairs in the RSA public-key encryption method.
Is primary topic of
Extended Euclidean algorithm
Label
enExtended Euclidean algorithm
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Additive inverse
Algebraic field extension
Arithmetic
Bézout's identity
Bijective
Category:Articles with example pseudocode
Category:Euclid
Category:Number theoretic algorithms
Certifying algorithm
Charles E. Leiserson
Clifford Stein
Coding theory
Computer algebra
Computer program
Computer programming
Content (algebra)
Coprime
Cryptography
Euclid's lemma
Euclidean algorithm
Euclidean division
Euclidean division of polynomials
Euclidean domain
Field (mathematics)
Finite field
Finite field arithmetic
Greatest common divisor
Integer overflow
Integral part
Introduction to Algorithms
Irreducible polynomial
Kuṭṭaka
Leading coefficient
Linear congruence theorem
Modular arithmetic
Modular multiplicative inverse
Monic polynomial
Multiplicative inverse
nZ
Parallel assignment
Polynomial greatest common divisor
Prime field
Prime number
Primitive polynomial (ring theory)
Quotient ring
Resultant
Ronald L. Rivest
RSA (algorithm)
Simple extension
Subresultant
The Art of Computer Programming
Thomas H. Cormen
Unit (ring theory)
Univariate polynomial
SameAs
Algorisme d'Euclides ampliat
Algorithme d'Euclide étendu
Algoritmo de Euclides estendido
Algoritmo esteso di Euclide
Erweiterter euklidischer Algorithmus
Extended Euclidean algorithm
Giải thuật Euclid mở rộng
Išplėstinis Euklido algoritmas
m.0pd13
NF4m
Q1362750
Razširjeni Evklidov algoritem
Rozšířený Eukleidův algoritmus
Rozšírený Euklidov algoritmus
Uitgebreid algoritme van Euclides
Проширени Еуклидов алгоритам
Расширенный алгоритм Евклида
Розширений алгоритм Евкліда
الگوریتم تعمیم‌یافته اقلیدس
خوارزمية إقليدس الممددة
扩展欧几里得算法
SeeAlso
Extended GCD algorithm
Polynomial greatest common divisor
Subject
Category:Articles with example pseudocode
Category:Euclid
Category:Number theoretic algorithms
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Extended Euclidean algorithm?oldid=1113184203&ns=0
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