Reference no: EM133911706

Cryptography Algorithms and Implementation

Assessment 1:

Introduction
You will submit work in tutorial activities during the study period. This is an individual assessment.
Part A Classical Encryption

Task:
You are given the following encrypted message:
gsrh rh z hvxvgrlm
Visit the website: Boxentriq Cipher Identifier
Paste the encrypted message into the tool and identify the cipher used.
Use the linked decryption tool provided by Boxentriq to automatically decrypt the message.
Explain the difference between:
Stream Ciphers vs. Block Ciphers
10

Substitution Ciphers
Classify the identified cipher (e.g., Atbash) and explain whether it is a stream, block, or substitution cipher.
Discuss the strengths and weaknesses of the cipher in terms of cryptographic security.
Include screenshots of:
Cipher identification result
Decryption tool interface
Final decrypted message

Task:
You are required to encode and decode your student number using the Vigenère Cipher.
Visit the website: Vigenère Cipher Tool - Boxentriq
Use a keyword of your choice (e.g., your first name or "SECURE") to:
Encrypt your student number (e.g., 12345678) by converting it into a text format (e.g., onetwothreefourfivesixseveneight)
Decrypt the resulting ciphertext using the same keyword
Take screenshots of:
The encryption process
The ciphertext
The decryption result
Explain:
How the Vigenère Cipher works
Why it is considered a polyalphabetic substitution cipher
Its strengths and weaknesses in modern cryptography

Using the Python3 code example in Geeks for Geeks test your answers (show screenshots).

One way to solve the key distribution problem is to use a line from a book that both the sender and the receiver possess. Typically, at least in spy novels, the first sentence of a book serves as the key. The particular scheme discussed in this problem is from one of the best suspense novels involving secret codes, Talking to Strange Men, by Ruth Rendell. Work this problem without consulting that book!

Consider the following message:

koeywduz dk omewzbuof ucftz gcw ojozwcmo

This ciphertext was produced using the first sentence of a different book:
The fog rolled in from the sea and the lanterns flickered in the cold breeze.
Tip:
A → T
B → h
C → e
D → f
E → o
F → g
G → r
H → l I → d
J → i
K → n
L → s
M →a
N →m
O → c
P → b
Q → v
R →w
S → k
T → u
U → y V → j W →x
X → q
Y → z
Z → p
Decode the message: koeywduz dk omewzbuof ucftz gcw ojozwcmo

Hint: The original plaintext is a meaningful sentence related to cybersecurity. Show your workings.
Part B Encryption Calculations
Show all steps in solving RSA when p = 7 and q = 19, e = 5. M (message) = 5.

Research and explain how prime numbers are calculated and the algorithms used to calculate RSA. Explain the steps in the Man-in-the-Middle Attack.
AES
Given the plaintext {101112131415161718191A1B1C1D1E1F} and the key {02020202020202020202020202020202}:
Show the original contents of State, displayed as a 4 × 4 matrix.
Show the value of State after initial AddRoundKey
Show the value of State after SubBytes - use Table provided below.
Show the value of State after ShiftRows
Show the value of State after MixColumns

Part C Encryption Implementation and Applications
The Hill Cipher takes a letter and converts it to a number form. E.g. A = 0, B = 1, C = 2, ...
e.g. Message: ‘DOG' = [3 14 6]
Covert the key into a 3x3 Matrix, Key: ‘GYBNQKURP'.
Multiple the Matrix together (use can use Octave Online). "mod 26" the resultant to get the cipher text.
Reverse the Ciphertext to recover the Message.
The Extensible Authentication Protocol (EAP) is widely used in secure network access.
Explain how EAP facilitates multiple authentication mechanisms (e.g., certificates, smart cards, biometrics) using encryption-based terminology. Get Assignment Help from trusted tutors.
Your answer should include references to key exchange, identity protection, and session key derivation.

You are hired to design a secure access control framework for a multinational company with varying levels of data sensitivity.
For each of the following models, recommend whether encryption should be used, and if so, specify the type (e.g., symmetric, asymmetric, hybrid) and key management strategy:
DAC (Delegated Access Control)
MAC (Mandatory Access Control)
ABAC (Attribute-Based Access Control)
Rule-Based Access
Risk-Adaptive Access
Identity-Based Access
Organization-Based Access
Support your recommendations with examples of how encryption enhances or complicates enforcement in each model.
You are conducting a forensic investigation on a compromised network.
Draw and explain the Authentication Header (AH) used in IPsec for both Transport and Tunnel modes.
Design a hash-based system to track and verify file integrity across multiple endpoints.
Explain how Merkle Trees and Blockchain structures use hashing to ensure tamper-proof logging and traceability.
Define a digital footprint for a computing device and explain how it can be calculated and used in forensic audits.