This is my small project in Python. The user selects mode  encrypt or  decrypt and input keys. The program gets input from the console or the user file depending on the user's chosen mode and encrypts user text using a four-square cipher, which works with two keys, output text in the console, or file  output.txt. The same thing happens during decryption, and the program decrypts user text instead of encryption. The key may be any text; the program filters it and gets the desired characters.

1. Install a Python interpreter if you don't have one (or use online interpreters).
2. Clone this repo or copy code from file  encryptor.py
3. Put it in the Python interpreter.
4. If you want to input your text from a file, create your own input.txt file and write your text there.
5. Run code.
6. Congrats! Now you can encrypt your secret text and send it to your friends without worrying about its safety because, without a decryptor it's just a bunch of incomprehensible characters :)

References:

• https://en.wikipedia.org/wiki/Four-square_cipher
• http://www.crypto-it.net/eng/simple/four-square.html