DES Python Script

To use below python code, copy & paste to any text editor (e.g. Sublime Text) as a python file. Then, all you need to do is to run on your command line or terminal (Pyhton3 needs to be installed). Have Fun ! #DataEncryptionStandard Encryption Protocol Python(3.6) Implementation by otapsin for CryptoQuantus. #Adapted from, """" #Initial … Continue reading DES Python Script

V. 2,3-DES & AES

2-DES (Double) Double-DES has two different encryption phases with two different keys (K_1, K_2) such that: Ciphertext (Encryption): Enc (K2, Enc(K1, P)) Plaintext (Decryption): Dec(K1, Dec(K2, C)) Meet in the Middle Attack Meet-in-the-middle is a known plaintext attack, that targets block cipher cryptographic functions, relies on exponentially reducing the number of brute force permutations required to … Continue reading V. 2,3-DES & AES

II. Information Entropy & Cryptography (Brute Force and Cryptanalysis)

Brute Force Attack As the name suggests, "Brute Force Attack", the process is based on testing all possible keys until find the correct key. Let's consider that the attacker finds out the correct key after trials. We have 4 keys such as, k_1-(00), k_2-(01), k_3-(10), k_4-(11) where information entropy of the system is 2 bits … Continue reading II. Information Entropy & Cryptography (Brute Force and Cryptanalysis)

Information Entropy (Simplified)

Dr. C. Shannon Information Entropy The information entropy (a.k.a Shannon’s Entropy) describes the disorder of the system. Let’s consider coin flipping system, where there are two possibilities for output such as head or tail. Hence, we may consider the system with 1-bit information (e.g. “0” for head and “1” for tail) and there is %50 chance … Continue reading Information Entropy (Simplified)

I. Cryptography: 101

Cryptography Terminology Cryptography, the study of encryption and decryption techniques. Cryptanalysis, codebreaking and deciphering ciphertext without the key. Cryptology, the field of cryptography and cryptology. Alice, Bob & Eve Framework Alice sends a message to Bob and Eve (stands for eaves dropper) wants to get the message. Here; there are, classical (e.g. Caesar cipher) and modern … Continue reading I. Cryptography: 101