Key Components for Encryption/Decryption:
Key Components for Encryption/Decryption Plugboard 3 Rotating Removable Rotors Reflector
Sample Encryption/Decryption:
Sample Encryption/Decryption
Enigma:
Enigma
Enigma Properties:
Enigma Properties 3 rotors 26x26x26 = 17,576 initial settings
Rotor order 3x2x1 = 6 possible arrangements
Swapping 6 letters 100,391,791,500
Approximately 1016 = 10,000,000,000,000,000 keys
Later versions of the Enigma had even more keys.
Swapped more than 6 letters
Selected 3 rotors from set of 5
Ciphertext-Only Attack:
Ciphertext-Only Attack Developed by James Gillogly. Find initial rotor setting and rotor order.
Uses Index of Coincidence.
Iterate through all possible initial rotor settings and rotor orders with no plugboard.
Largest IOC is the most likely rotor arrangement.
Uses rotor settings from step 1.
Finds one new plugboard setting for each iteration.
Decrypt the text with every possible character pair.
25x26 = 650 pairs.
Trigram analysis on the 650 decrypted texts. Add the setting to the plugboard with the best decrypted text.
Step 1: Step 2:
Ciphertext-Only Attack Step 1 Results:
Ciphertext-Only Attack Step 1 Results
Ciphertext-Only Attack Step 1 Results Cont.:
Ciphertext-Only Attack Step 1 Results Cont.
Current Trigram Results:
Current Trigram Results Attempted analyzing text based on most probable trigrams in English plaintext.
+1 for “good” trigram, -1 for “bad.”
Highest score wins.
To many swaps initially to be accurate.
Currently working on developing trigram statistics for partially decrypted Enigma texts to use in the initial rounds of finding the plugboard settings.