Simplified DES (S-DES) is an educational tool designed to help students learn the structure of DES using smaller blocks and keys.

• Feistal block cipher
• Plaintext: 8 bit
• Key: 10 bit
• Ciphertext: 8 bit

Use the SimplifiedDES class in your program as follows.

For encryption:

from sdes import SimplifiedDES

plaintext = 0b10101010
key = 0b1110001110
ciphertext = SimplifiedDES(key).encrypt(plaintext) # 0b11001010

For decryption:

from sdes import SimplifiedDES

ciphertext = 0b11001010
key = 0b1110001110
plaintext = SimplifiedDES(key).decrypt(ciphertext) # 0b10101010

• Check out theory.pdf for more information and worked out examples.
• Simplified DES as an excel workbook
• Data Encryption Standard

Mayank Jain

MIT