/encrypted-chat

Primary LanguageJava

encrypted-chat

How to use

Locally

Client 1

java MainChat localhost 1234 localhost 1235

Client 2

java MainChat localhost 1235 localhost 1234

Remote clients

Client 1

java MainChat hostA 1234 hostB 1235

Client 2

java MainChat hostB 1235 hostA 1234

How was the chat made?

  1. We used this project as a starting point. There is no encryption though, so everything going through the network is in plain text.
  2. As the application is supposed to be point to point, we removed the server and the logic to manage multiple clients. We focused on having a connection that allowed two clients to exchange messages in plain text.
  3. When we accomplished the above objective, we introduced the Diffie-Hellman algorithm to exchange a secret key.
  4. Finally, we used the key to encrypt and decrypt all the messages of the communication using AES-128.

The program was tested and is known to work with two computers in the same network.

Conclusions

It is relatively easy to create a secure chat using the built-in encryption libraries in the JDK. The security of the application depends on the size of the prime number P.