Number - Gf(2) - Galois Field 2

Galois Field 2 has just two elements: 0 and 1

Usual algebraic laws still hold, e.g. multiplication distributes over addition

Addition is like exclusive-or:

vector addition

  1 1 1 1 1
+ 1 0 1 0 1
= 0 1 0 1 0

Adding is the same than subtracting in gf2.

Multiplication is like ordinary multiplication

The probability distribution of the cyphertext does not depend on the plaintext.

Idea is the basis for cryptosystem: the one-time pad. If each bit is encrypted with its own one-bit key, the cryptosystem is unbreakable