DrewBarlow / SDES

MAIN FUNCTIONS:

• sdes_encipher_ECB(plaintext, key)
• sdes_decipher_ECB(ciphertext, key)
• dsdes_encipher_ECB(plaintext, key1, key2)
• dsdes_decipher_ECB(ciphertext, key1, key2)
• sdes_encipher_CBC(plaintext, key, iv)
• sdes_decipher_CBC(ciphertext, key, iv)
• dsdes_encipher_CBC(plaintext, key1, key2, iv)
• dsdes_decipher_CBC(ciphertext, key1, key2, iv)

..

NOTE:

I did not do official packaging with setuptools or anything.

Therefore, I recommend either copying sdes/ into attacks/ or making a symlink.

Answers to Questions

Keys used to produce the ciphertext in the known pairs:

• Key 1: 0b1100111111; and,
• Key 2: 0b0101010011.

Time taken to determine the key pair (meet in the middle):

• 2.902s.

Time taken to determine the key pair (brute force):

• 8176s; or,
• 136m16s; or,
• 2h16m16s.

Decryption of the text encrypted using CBC mode:

• "Congratulations on your success!"
• Code for this can be found in main.py at line 189.

A list of the S-DES weak keys:

• 0b0000000000; and,
• 0b1111111111; and,
• 0b0111101000; and,
• 0b1000010111.