Data Encryption Standard

The Data Encryption Standard (DES) is a symmetric-key cryptographic algorithm that was widely adopted in the late 20th century. Developed from IBM’s Lucifer cipher, DES was standardized by the U.S. NBS in 1977, with input from the NSA. The official specification is available here.

Due to advances in cryptanalysis, DES is now considered insecure. It has largely been superseded by the Advanced Encryption Standard (AES).

This repository contains an implementation of DES that strictly follows the official specification.

Usage

This repository contains the core DES algorithm in the file src/des.c and also includes a minimal cli-wrapper src/cli-wrapper.c for testing. Follow these steps to try it:

• Clone the repository and move in:

  git clone https://github.com/noinoiexists/Data-Encryption-Standard.git && cd Data-Encryption-Standard

• Compile the code:

  gcc src/des.c src/cli-wrapper.c src/operation-modes.c -o des-minimal -Wall -Wextra

The tool can be run using ./des-minimal.

Example

$ ./des-minimal
Plaintext:
This is DES

Key (8 bytes):
icebergs

Mode (1=CBC, 2=ECB):
1

IV (8 bytes, optional):
vacation

Ciphertext (hex):
d7fb39281da198897db700ff60be9ebd

To-do

• Core Data Encryption Standard Algorithm
• PKCS#5/7 Padding
• Multi-block Encryption
  • Electronic Code Book (ECB) mode
  • Cipher Block Chain (CBC) mode
• Decryption
• Enhanced command-line interface

Licence

This implementation was created by me, Nithik R and is protected under the MIT Licence. You can read more about it in the LICENCE file.