Question | Answer |
Caeser Cipher (Substitution Cipher) | Simple Substitution, Shift Characters 3 spaces, A=D, B=E, C=F...etc, Substitution Ciphers are subject to pattern analysis |
Scytale | Spartans used to communicate messages to generals in the fields, Wrapped tape around a rod, Diameter of the rod is the pre-agreed upon secret(key) |
Vignere | First polyalphabetic ciper, Key work is agreed upon ahead of time, first letter of the key is matched up against first letter of the message, and so on. |
Vernam | One Time Pad, Only mathematically unbreakable form of cryptography, key only used once, Pad as long a s message, unpredictable. Key Pad must be delivered and stored securely |
Enigma Machine and Purple Machine | Used by the Germans and Japanese in WWII, Breaking the cryptography of these devices is credited with reducing the length of the war. |
Running Key Cypher | Encryption Key is as long as the message itself and is often chosen from a common book. |
Transposition Cipher | Use an encryption algorithm to rearrange the letters of a plaintesxt message, forming the ciphertext message |
Block Cipher | Operates on chunks of a message and apply the encryption algorithm to an entire message block at the same time. |
Stream Cipher | Operates on one character or bit of a message at a time. |
Confusion | When the relationship between the plaintext and the key is so complicated that the attacker can't continue altering the plaintext and analyzing the resulting ciphertext to determine the key. |
Diffusion | When a change in plaintext results in multiple changes spread throughout the ciphertext. |
Data Encryption Standard | 64-bit block cipher that has 5 modes of operation. Uses 16 rounds of XOR operations to generate the ciphertext. |