Question1: 10 marks (300 words, 150 words approx. for each question)
Question1: 10 marks (300 words, 150 words approx. for each question)
Encrypt an image file (.bmp) using AES-ECB and AES-CBC modes of operation and answer the following questions:
1. What is the difference between the two generated cipher images?
2. Which encryption is better AES-ECB or AES-CBC? And why?
Notes:
Assume Key and Nonce of your choice.
You can use openssllibrary to perform this lab activity
Example of AES image encryption using openssllibrary A Walkthrough on AES Image Encryption: https://medium.com/@JakenH/today-im-going-teach-you-how-to-encrypt-a-simple-picture-that-you-can-download-here-141ce9b0b738
Submit your two images and the answer to the above questions.
Question 2: 10 marks (300 words, 100 words each)
Read this article, and provide answers to the following:
https://crackstation.net/hashing-security.htm#properhashing
1) Why are salts not kept as secrets?
2) Is there any risk if the same salt is reused for several hashes on a user?
3) Use the CrackStation to crack the three password hashes below and write the answer to the following: a) What is the password?
b) What hash algorithm is used?
Hash 1: 6384E2B2184BCBF58ECCF10CA7A6563C
Hash 2: 4E40E8FFE0EE32FA53E139147ED559229A5930F89C2204706FC174BEB36210B3
Hash 3: 5994F091C5CBC05EE2DF38DA2C54EA5BE663D54E
Question 3: 15 marks (400 words)
Complete the following cyber range lab and answer the corresponding quiz:
Cyber Range: Introduction to public-private keys and SSH server configuration
Question 4: 20 marks (450-500 words)
Complete the following CYRIN Lab:
Cyber Range: VPN Server Configuration with OpenVPN
Question 5: 10 marks (300 words)
In their 1978 paper, Needham & Schroeder have 7 steps in the definition of the NSPK Protocol [1].
What are these additional steps used for and why don't we need them here?
[1] Roger M Needham and Michael D Schroeder. Using encryption for authentication in large networks of computers. Communications of the ACM, 21(12):993999, 1978
Question 6: 10 marks (300 words)
In their 1987 paper, Needham and Schroeder respond to the freshness problems in their NSSK
protocol. How does the extended NSSK protocol detailed in the paper below protect against these
attacks?
Roger M. Needham and Michael D. Schroeder. Authentication revisited. ACM SIGOPS Operating
Systems Review, 21(1):77, 1987.
