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GF(P)

What is GF(P)?

GF(P) or Galois Field of prime order is a finite mathematical field containing exactly p elements (where p is a prime number). It's a fundamental concept in abstract algebra and cryptography, providing a structured way to perform arithmetic operations within a finite, prime-sized set.

Key Components:

   1. Prime number p
   2. Elements {0, 1, 2, ..., p-1}
   3. Modular arithmetic
   4. Closed algebraic operations

Core Rules:

   1. All arithmetic done modulo p
   2. Elements range from 0 to p-1
   3. Supports addition, subtraction, multiplication, division
   3. Division uses modular multiplicative inverse

Basic Operations:

   1. Addition: (a + b) mod p
   2. Subtraction: (a - b) mod p
   3. Multiplication: (a * b) mod p
   3. Division: Multiplicative inverse

Example with GF(5):

Elements: {0, 1, 2, 3, 4}
Addition:
   • 3 + 4 = 2 (mod 5)
   • 2 + 3 = 0 (mod 5)

Multiplication:
   • 3 * 4 = 2 (mod 5)
   • 2 * 3 = 1 (mod 5)

Multiplicative Inverse:
   • In GF(5), 2 * 3 = 1 (mod 5))
   • So 3 is multiplicative inverse of 2

Significant Properties:

   • Commutative operations
   • No element has zero divisors
   • Every non-zero element has inverse
   • Closed under all operations

Video for explanation