1. Publicly transport a large prime number p and it’s primitive root g
  2. Alice chooses a secret a and compute A = g^a mod p
  3. Bob chooses a secret b and compute B = g^b mod p
  4. Publicly trnasport A and B
  5. Now and are the same after , this is the secret key.


Eve only know and , to know we need to solve the Discrete Logarithm problem


import random
def generate_key(p, g, a):
    A = pow(g, a, p)
    return A
def compute_secret_key(p, B, a):
    s = pow(B, a, p)
    return s
# Example usage
p = 23
g = 5
a = random.randint(1, p-1)
b = random.randint(1, p-1)
A = generate_key(p, g, a)
B = generate_key(p, g, b)
s1 = compute_secret_key(p, B, a)
s2 = compute_secret_key(p, A, b)
assert s1 == s2
print("Shared secret key:", s1)