What is this?

An implementation of the AES algorithm in Python 3 and the block cipher operation of mode ECB, CBC and CTR.

Why did you do this?

Because of learning purposes and also for being a project for Information and Coding Theory course.

Can I use it?

Yes, for sure.

Basic usage

Setup

pip3 install -r requirements.txt
chmod +x crypt.py

Encrypt

Encrypt "file_to_encrypt" using block cipher mode of operation CTR and with a key of length 256 bits. Output file "file_name_encrypted"

./crypt -i <file_to_encrypt> -o <file_name_encrypted> -m CTR -l 256

The key used for encryption will be displayed and saved in the file "key.txt".

Decrypt

The key used for decryption will be read from "key.txt"

./crypt.py -d -i <file_to_decrypt> -o <file_decrypted> -m CTR -l 256

References

1. Nist Fips 197
2. The Design of Rijndael
3. Block cipher mode of operation
4. Using Padding in Encryption