At first we make another RX/TX pins manually by including "SoftwareSerial" header.
We can then input a string into the board and view it encrypted in our own RX/TX and decrypt it again in the original RX/TX of the board.
Encrypts and decrypts are done using the "AESlib" header and can be designed and complex.
All these explanations can be viewed as tested in the video of test folder.