Assignment 3

COMPSCI 316: Cyber Security, Semester 2, 2024

This assignment is worth 75 marks and counts towards  10% of the course grade.

The submission deadline is Friday, October 18 NZ Time. No late submissions are accepted. The assignment must be submitted through Canvas. The only acceptable format is PDF.

Please keep your answers concise and under 300 words, and you are expected to use APA or IEEEreferencing style. in this assignment.

Note. Sharing assignment solutions does not help in your learning. Consequently, our academic integrity policy does not permit sharing solutions or source code leading to solutions. Violation of this will result in your assignment submission attracting no marks, and you may also face disciplinary actions. Therefore, please do not share assignments, assignment solutions, or source code leading to assignment  solutions. Do not publish or make available your assignments or solutions online, for  you will be liable if someone copies your solution. Please talk to us if you have any doubts about what is legit and what is not.

Do not leave your computers, devices, and belongings unattended — you must  secure these at all times to prevent anyone from accessing your assignments or solutions.

Question I. Anonymous Communication (30 marks)

The company you work for is considering implementing anonymous communication over the Internet. However, there is a lot of debate between the parties involved as to which of the below technologies should be the best fit for the business model.

As a security consultant, you are tasked to present various risks and opportunities associated with the following two technologies: (a) Tor, (b) VPN.

1.  Present a detailed comparative analysis between the above outlined technologies  with respect to the following parameters:     [5 x 3 = 15 marks]

●   Speed

●   Cost

●   Security

●   Accountability

●    Ease of use

2.  Discuss how Tor and VPN can be configured together by explaining the below configurations:                                     [5 x 2 = 10 marks]

●   Tor over VPN

●   VPN over Tor

For each of these configurations, describe the flow of data with a diagram, and present the opportunities and risks associated with the configurations.

3.  Choose one from the below list as your final recommendation, and provide justification for the same.             [5 marks]

●   Tor   ●   VPN

●   Tor over VPN

●   VPN over Tor

State any assumption(s) you have made to answer the question.

Question II. Blockchain Technology (35 marks)

Part I

1.  Explain the role of the following cryptographic primitives in achieving various security goals in blockchain technology.              [3 x 3 = 9 marks]

●   Cryptographic nonce

●   Digital Signature

●   Cryptographic Hashes

For each of the primitives, mention which security goal(s) is/are achieved, and how  they are achieved. State any assumption(s) you have made to answer the question.

2.  Using a diagram, analyse and explain how a distributed ledger works. Explain how it differs from a traditional centralized ledger.                           [3 x 2 = 6 marks]

3.  Explain how blockchain technology prevents ‘double-spending’ attacks, and discuss one potential vulnerability or limitation of this approach.                [5 marks]

Part II

The government of your country is considering introducing a new project named ‘Blockchain-based Healthcare Data Management System’ . This project will involve a decentralised  database of patients’ sensitive data   using  blockchain  technology. Electronic  Health  Records  (EHRs),  comprising  this  data,  will  be  shared  across healthcare organisations across the country, such that healthcare providers, medical technicians, and patients can access the data.

1.  Explain with a data-flow diagram how the decentralised architecture can be designed using blockchain technology.                        [5 marks]

2.  Which type of blockchain should be used for the privacy of patients’ data? Justify   your answer.                        [5 marks]

3.  Explain the advantages and disadvantages of introducing blockchain technology in healthcare.                                [5 marks]

State any assumption(s) you have made to answer the above questions.

Question III DoS Attacks (10 marks)

1.  The organisation you work for is planning to implement ‘anti-spoofing’ and

‘directed broadcast filters’ to safeguard their servers against Denial of Service

(DoS) attacks. As a cybersecurity consultant, you have been tasked with

presenting a risk analysis report both pre- and post-implementation of these

measures. This report must include whether the servers remain susceptible to

any type of DoS attacks after implementing the above filters, and if so, suggest countermeasures that could be taken to reduce them.                        [8 marks]

State any assumption(s) you have made to answer the question.

2.  Explain how ‘ Hidden Services’ can be used to protect against DDoS attacks. [2 marks]