T215B: Communication and information technologies (II)

T215B: Communication and information technologies (II)
Spring 2016/2017
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Tutor-Marked Assignment
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Cut-off date: To be assigned
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Total Marks: 100
Important Note: This TMA consists of three questions.
TMA Contents
Question 1 (36 marks)
Question 2 (32 marks)
Question 3 (32 marks)
Plagiarism Warning:
As per AOU rules and regulations, all students are required to submit their own TMA work and avoid plagiarism. The AOU has implemented sophisticated techniques for plagiarism detection. You must provide all references in case you use and quote another person's work in your TMA. You will be penalized for any act of plagiarism as per the AOU's rules and regulations.
Declaration of No Plagiarism by Student (to be signed and submitted by student with TMA work):
I hereby declare that this submitted TMA work is a result of my own efforts and I have not plagiarized any other person's work. I have provided all references of information that I have used and quoted in my TMA work.
Name of Student:………………………………..
Signature:…………………………………………...
Date:……………………………………………………
2
Question 1: Virtual Private Network (VPN)
This question carries 36 % of the marks for this assignment.
One of the topics introduced in T215B is the Virtual Private Network (VPN), as an example of a mechanism to establish a secure remote access connection across an intermediary network, often the Internet. VPNs allow remote access, remote control, and highly secured communication within a private network. Based on this information as well as the internet and other resources (e.g., books and AOU e-library), write a short report explaining the following factors:
 Give a brief definition of VPN and what is it used for. (6 marks)
 Explain the business and personal uses of VPN. (6 marks)
 Describe some benefits of a VPN? (6 marks)
 What are the limitations of a VPN? (6 marks)
 What is the relationship between encryption and VPNs? (6 marks)
Short Report Writing:
Please adhere to the following guidelines for writing your report:
Your report should be between 500 and 600 words in length. Under-length and over-length reports will be penalized.
Your report should include at least two figures and/or tables. Do not forget to include a caption for each figure/table and to use cross-referencing. (2 Marks)
Ensure that your report has an appropriate structure and style. (2 marks)
In order to be allocated marks for your answer you must demonstrate the quality of your research via the references/citations that you include per question. You must cite all the references i.e. any internet web site, book, journal, article etc. that you have used as a source of information for your report (2 marks)
You are advised to remind yourself of the issues concerning plagiarism.
Question 2: Vigenère cipher
This question carries 32% of the marks for this assignment.
Use the Vigenère cipher to DECRYPT the following ciphertext: “OGTJQPPBJGQXECGXMG” knowing that the keyword ‘optical’ was used for encryption. Write the original plaintext as readable text? Show your work in details (in the form of table). (Hint: find the decryption key).
Table below helps you to find the code equivalent to each letter.
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Question 3: Practical on Hash function / Triple DES:
This question carries 32 % of the marks for this assignment.
This part is a practical one. It involves applying online tools for achieving hash function and Triple DES Encryption/Decryption algorithm.
Part A: Hash function: (16 Marks)
a) Apply an online tool hash function using the MD5 algorithm to calculate the hash value for the following string: “Welcome to course T215B!” (5 marks)
b) Apply again an online tool hash function using the MD5 algorithm to calculate the hash value for the following string: “Welcome to course T215B” (5 marks)
For answering both parts a and b, you need to include screenshots that shows the application of the hash function along with the proper output result for each part.
c) Compare the values obtained from both parts a and b. What can you deduce? (6 marks)
Part B: Triple DES Encryption (16 marks)
a) Apply an online tool Triple DES encryption algorithm using the following parameters:
Key value=your ID number, for example: 132144; Mode value= ECB;
Encode the output using: “Hexadecimal”
To encrypt the following plaintext: “faculty of computer studies” (5 marks)
b) Apply the online tool Triple DES encryption algorithm using the following parameters:
Key value=your ID number; Mode value= CBC; encode the output using: “Hexadecimal”
To encrypt the same plaintext: “faculty of computer studies” (5 marks)
For answering both parts a and b, you need to include screenshots that shows the application of the encryption algorithm with the specified parameters along with the proper output result for each part.
c) Compare the values obtained from both parts a and b. What can you deduce? (6 marks)
Reference for online tools: The Online tools required are available through the following website:
https://www.tools4noobs.com/online_tools/
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End of TMA questions