Rust Simplified Data Encryption Standard (SDES)

for learning purposes

Program runs with Cipher Block Chaining (CBC) mode.

To better understand how the encryption algorithm and cbc work:

• ./info/cbc.pdf
• ./info/s-des.pdf

Usage:

Clone the program and run it with cargo (Rust's package manager)

Both parties: sending (encrypting), and receiving (decrypting), need to securely share a 10-digit binary symmetric key, and an 8-digit binary initialization vector. If the key, initialization vector, and file match, encryption and decryption should work for any type of file.

Run the program with the following arguments:

Encryption:

cargo run <key> <vector> <plaintext_filename> <ciphertext_filename>

Decryption:

cargo run <d> <key> <vector> <ciphertext_filename> <plaintext_filename>

Example:

File: andromeda.jpg (plaintext)

Encrypting ./files/andromeda.jpg with key 0111111101 and initialization vector: 10101010:

File: andromeda.jpg.encrypted (ciphertext)

File is now meaningless to image viewers, opening it produces this:

Decrypting file ./andromeda.jpg.encrypted with key 0111111101 and initialization vector: 10101010:

Produces the original file. I tried to write the code as close to the description of the algorithm as possible for the sake of readability.

P.S.: This program is for learning purposes only, this encryption can be easily broken, so do not rely on it for important files!