# Diffie Hellman 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. ## Step 0 The test program supplies prime numbers p and g. ## Step 1 Alice picks a private key, a, greater than 1 and less than p. Bob does the same to pick a private key b. ## Step 2 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. ## Step 3 Alice and Bob exchange public keys. Alice calculates secret key s. s = B**a mod p Bob calculates s = A**b mod p The calculations produce the same result! Alice and Bob now share secret s. To run the tests simply run the command `go test` in the exercise directory. If the test suite contains benchmarks, you can run these with the `-bench` flag: go test -bench . For more detailed info about the Go track see the [help page](http://exercism.io/languages/go). ## Source Wikipedia, 1024 bit key from www.cryptopp.com/wiki. [http://en.wikipedia.org/wiki/Diffie%E2%80%93Hellman_key_exchange](http://en.wikipedia.org/wiki/Diffie%E2%80%93Hellman_key_exchange) ## Submitting Incomplete Problems It's possible to submit an incomplete solution so you can see how others have completed the exercise.