exercism/go/diffie-hellman

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.

Source

Wikipedia, 1024 bit key from www.cryptopp.com/wiki. 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.