The key exchange problem describes ways to exchange whatever keys or other information are needed for establishing a secure communication channel so that no one else can obtain a copy.
- Alice locks the box with her lock and sends it to Bob
- Bob locks the box with his lock and sends it back to Alice
- Alice removes her lock and sends it back to Bob
- Bob removes his lock
- Double Encryption Transfer
- Both parties generate random keys and
- Sender sends encrypted message
- Receiver encrypts received message and sends it back
- Sender decrypts message and sends it again (only valid if operation is associative!)
- Receiver decrypts final message
Diffie Hellman
A way of performing key exchange over an insecure channel.