Enigma machine, Lap 1

UF CSCI Lab – Private Key Cryptography

csci 302.01 lab 1 enigma v1.1.docx page 1 of 2

Overview This lab consists of three activities. Activity 1 involves executing an electronic model of an Enigma machine and examining its source code. Activity 2 involves encrypting plaintext and decrypting the ciphertext from the electronic model, and comparing the output. Activity 3 involves discussion of Enigma as a symmetric cryptographic platform and the associated key exchange problem. A written lab report completes the assignment.

Additional background information can be found at: https://en.wikipedia.org/wiki/Enigma_machine http://www.bbc.co.uk/ahistoryoftheworld/objects/Vhi0q4vZTIuNRH6tkNTjmw https://www.iwm.org.uk/history/how-alan-turing-cracked-the-enigma-code https://en.wikipedia.org/wiki/The_Imitation_Game https://simonsingh.net/books/the-code-book/ http://wiki.franklinheath.co.uk/index.php/Enigma/Paper_Enigma Activity 1 – Electronic Enigma Machine Using the Enigma simulation found at https://people.physik.hu-berlin.de/~palloks/js/enigma/index_en.html#top , execute the simulator for Universal Enigma v2.5 EN. Select Enigma model M3 (upper right drop down). Observe the cryptographic algorithm at work by configuring the reflector, rotors and initial key setting prior to encrypting a plaintext message and observing the output ciphertext. Reverse the process to decrypt ciphertext into its plaintext format. Examine the HTML javascript source code for the electronic Enigma simulator to complete this activity. Activity 2 – Encryption and Decryption using Enigma Using the validation operations provided below, confirm that the electronic Enigma model produced the same ciphertext from the input plaintext message. Reverse the process to produce the same plaintext from an input ciphertext message. If the output is not the same, explain why. Activity 3 – Symmetric Cryptography & Key Exchange Using the background information referenced in this assignment, discuss the effectiveness of Enigma as a symmetric cryptographic platform relative to its use during WWII. Discuss the associated problem of key exchange, relative to symmetric cryptography, and how this problem contributed to cracking the Enigma cryptographic platform. Lab Report Write a brief lab report describing your observations regarding operation of the electronic model and your thoughts on Enigma as a symmetric cryptographic platform and the associated key exchange problem. Use the background information provided above to help frame your thoughts, and include proper citations where necessary. Use screen shots to build labelled figures, charts and tables to support your findings. Upload your finished lab report to Canvas in the form of a Word document. Be prepared to discuss your findings in class.

UF CSCI Lab – Private Key Cryptography

csci 302.01 lab 1 enigma v1.1.docx page 2 of 2

Validation Operations - The following operations are intended to validate output using electronic Enigma model M3 (Army, Navy). Validation Operation #1 Click ‘New Session’ Reflector setting: B Rotor setting (L-R): 1-2-3 Key setting: A-B-C Encryption plaintext: CONGRATULATIONS ciphertext: aefae jxxbn xyjty Decryption ciphertext: aefae jxxbn xyjty plaintext: CONGR ATULA TIONS Validation Operation #2 Click ‘New Session’ Reflector setting: B Rotor setting (L-R): 1-2-3 Key setting: A-B-C Encryption plaintext: ENIGMA ciphertext: xyzau j Decryption ciphertext: xyzau j plaintext: ENIGMA Validation Operation #3 Click ‘New Session’ Reflector setting: B Rotor setting (L-R): 1-2-3 Key setting: A-B-R Encryption plaintext: TURN MIDDLE ciphertext: mabek gzxsg Decryption ciphertext: mabek gzxsg plaintext: TURN MIDDLE