encrypt

This is a simple, proof of concept implementation of three-pass protocol encryption. The encryption works as follows:

1. Sender multiplies every byte of its message by its key into a long
2. Sender sends the modified message to the receiver
3. Receiver multiplies every long of received message by its key
4. Receiver sends message back to sender
5. Sender divides every long of message by its key
6. Sender sends message back to receiver
7. Receiver divides every long of message by its key.
8. The message is now in plaintext at the receiver's end.

compiling

Just call make:

$ make

running

To start the receiver:

$ ./receiver <port> <key>

To start the sender:

$ ./sender <host> <port> <key>

The sender accepts exactly one line of input from stdout, sends it, and exits.