Discrete Math for Cryptography

In this class, We discuss Discrete Math for Cryptography.

The reader should have prior knowledge of discrete mathematics. Click here.

The concept we use in cryptography is finding GCD using an Euclidean algorithm.

The table below shows an example of finding the GCD of two numbers.

GCD(161, 28) = 7

The next concept we use in cryptography is congruence.

a congruence b mod n is a mod n = b mod n

We need to refresh the properties of congruence.

Fermat little theorem is also used in cryptography.

Euler’s theorem is also used in cryptography.

Group theory basics are needed for cryptography.

Given a group (z, +) where z is a set of integers.

The identity element of the group is zero.

The inverse of an element a is-a.