Diffie Hellman Key Exchange

A method used in End to End Encryption to generate the shared key through sharing public variables, combining them with private variables and ending up with both users having the same result.

Process

1. Alice has private key $a$, Bob has private key $b$, public variables $g$ and $n$ are stored. $g$ is a very small prime number $n$ is a very big prime number
2. Bob and Alice each calculate $g^{privatekey}\mathrm{mod}n$ and then share them with eachother.
3. Each user receives the other discrete logarithm key from the other and then raises it by their own private key this results in both users having the same symmetric key

Decryption

This is based off the Discrete Logarithm Problem that can be solved with:

• Diffie Hellman g Finding
• Baby-step Giant-step