Update README.md

README.md

@@ -4,42 +4,66 @@ Advanced Encryption Standard (AES) implementation in C
 AES is the most widely adopted symmetric encryption standard nowadays. This repository contains an implementation in C of the AES-128 algorithm. The program takes two arguments: a 32-bytes hexadecimal string representing the 128-bit input block, and another 32-bytes hexadecimal string representing the 128-bit key. It then outputs the corresponding ciphertext in hexadecimal form.
 
 
-![screenshot](https://github.com/user-attachments/assets/8173fe57-0254-48df-a4e8-ebc41d01ccd0)
+![image](https://github.com/user-attachments/assets/900b8428-7ed6-4c77-9a9c-df00db352c40)
 
-(Writing in progress)
+Screenshot taken after building the project with the build.bat file.
 
 
 Installation
 ------------
 
-First install Python 3.13.2 or above.  
-Then, make sure you have the following Python packages installed: `requests`, `pynput`.
-
-You can install these packages with:
+First make sure you have installed the GCC compiler v8.1.0 or above.  
+The `gcc --version` command should output:
 ```
-pip install requests pynput
+gcc (x86_64-posix-seh-rev0, Built by MinGW-W64 project) 8.1.0
+Copyright (C) 2018 Free Software Foundation, Inc.
+This is free software; see the source for copying conditions.  There is NO
+warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 ```
 
-Then, clone this repository and edit `keylogger.pyw` to add your own custom webhook URL at line 40.  
 
----
-Double-click on `keylogger.pyw`. You will not see anything as the program starts in background. You can check if the program has successfully started with the following command:
+Then, clone this repository in any location on your computer and double-click on `build.bat`.  
+You should now see the program's output.
+
+
+Usage and test vectors
+----------------------
+
+The program takes two arguments: a 32-bytes hexadecimal string representing the 128-bit input block, and another 32-bytes hexadecimal string representing the 128-bit key. It then outputs the corresponding ciphertext in hexadecimal form. You can find some test vectors on the official NIST website [on this page](https://csrc.nist.gov/projects/cryptographic-algorithm-validation-program/block-ciphers).  
+
+For example, with the following sample data set:  
 ```
-tasklist | findstr /I "python"
+KEY = 00000000000000000000000000000000
+PLAINTEXT = 6a84867cd77e12ad07ea1be895c53fa3
 ```
 
+The program should output:
+```
+CIPHERTEXT: 732281c0a0aab8f7a54a0c67a0c45ecf
+```
+
+To check this output, build the project and then execute this command:
+```
+main.exe 6a84867cd77e12ad07ea1be895c53fa3 00000000000000000000000000000000
+```
+
+You should now see the ciphertext `732281c0a0aab8f7a54a0c67a0c45ecf`.
+
 
 Future work
 -----------
 
 A few ideas to improve this project:
-- Add mouse's position capture and send this data to the server.
-- Automatically take a screenshot of the whole screen and send it to the server.
-- Get some system information with `os.system('systeminfo')` and send them to the server.
-- Automatically start the keylogger at computer start (thus not self-destroying it).
+- Add decryption part.
+- Test the implementation in ECB or CBC block cipher modes.
+- Rewrite the key expansion function in a cleaner way.
+- Add features for file encryption.
 
 License
 -------
 
 This work is shared under the [MIT license](LICENSE).  
-Do not use this program without appropriate permissions.
+
+The AES S-Box initialization function has not been written by me and have been taken from:  
+https://en.wikipedia.org/wiki/Rijndael_S-box (Accessed on March 21, 2025)  
+Original licence: CC BY-SA 4.0