Diffie-Hellman key exchange.
Alice and Bob use Diffie-Hellman key exchange to share secrets. They start with prime numbers, pick private keys, generate and share public keys, and then generate a shared secret key.
The test program supplies prime numbers p and g.
Alice picks a private key, a, greater than 1 and less than p. Bob does the same to pick a private key b.
Alice calculates a public key A.
A = g**a mod p
Using the same p and g, Bob similarly calculates a public key B from his private key b.
Alice and Bob exchange public keys. Alice calculates secret key s.
s = B**a mod p
s = A**b mod p
The calculations produce the same result! Alice and Bob now share secret s.
Sign up to Exercism to learn and master Go with 34 concepts, 140 exercises, and real human mentoring, all for free.