## How do you extend Euclidean algorithm?

The extended Euclidean algorithm

- Set the value of the variable c to the larger of the two values a and b , and set d to the smaller of a and b .
- Find the quotient and the remainder when c is divided by d .
- If r = 0, then gcd( a , b ) = d .

### What is difference between Euclidean and extended Euclidean algorithm?

The major difference between the two algorithms is that the Euclidean Algorithm is primarily used for manual calculations whereas the Extended Euclidean Algorithm is basically used in computer programs.

**Where is extended Euclidean algorithm used?**

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.

**What is extended Euclidean algorithm in cryptography?**

Extended Euclidean Algorithm is an extension of the Euclidean Algorithm that computes the greatest common divisor (GCD) of integers a and b. GCD is the largest integer that divides both a and b without any remainder.

## How do you prove Euclidean algorithms?

Answer: Write m = gcd(b, a) and n = gcd(a, r). Since m divides both b and a, it must also divide r = b−aq by Question 1. This shows that m is a common divisor of a and r, so it must be ≤ n, their greatest common divisor. Likewise, since n divides both a and r, it must divide b = aq +r by Question 1, so n ≤ m.

### What is Euclidean algorithm in CNS?

The Euclidean algorithm is an efficient method to compute the greatest common divisor (gcd) of two integers. It was first published in Book VII of Euclid’s Elements sometime around 300 BC. We write gcd(a, b) = d to mean that d is the largest number that will divide both a and b .

**How does extended Euclidean algorithm work?**

The Extended Euclidean Algorithm. As we know from grade school, when we divide one integer by another (nonzero) integer we get an integer quotient (the “answer”) plus a remainder (generally a rational number). For instance, 13/5 = 2 (“the quotient”) + 3/5 (“the remainder”).

**What is the significance of extended Euclidean algorithm with reference to RSA algorithm?**

Euclid algorithm and extended Euclid algorithm are the best algorithms to solve the public key and private key in RSA. Extended Euclid algorithm in IEEE P1363 is improved by eliminating the negative integer operation, which reduces the computing resources occupied by RSA, hence has an important application value.

## How is Euclidean algorithm used?

The Euclidean algorithm is a way to find the greatest common divisor of two positive integers, a and b. First let me show the computations for a=210 and b=45. Divide 210 by 45, and get the result 4 with remainder 30, so 210=4·45+30. Divide 45 by 30, and get the result 1 with remainder 15, so 45=1·30+15.

### How does Extended Euclidean Algorithm work?

**Why does Euclid GCD work?**

The Euclidean algorithm works because if x is a factor of A and x is a factor of B then x is a factor of A-B. So every factor of both A and B is a factor of A-B.