联系我们： 手动添加方式: 微信>添加朋友>企业微信联系人>13262280223 或者 QQ: 1483266981

THE UNIVERSITY OF SUSSEX
BSc and MComp THIRD YEAR EXAMINATION
Introduction to Computer Security
G6077
If you have extra time due to Reasonable Adjustments this is additional to the
exam duration below and has been added to your assessment on Canvas.
Date: Monday, 13 January 2025
Start: 09:30
Exam Duration: 2.5 hours (including 30 minutes for scanning, collating,
uploading)
Candidates should answer TWO questions out of THREE.
If all three questions are attempted only the first two answers will be marked.
Each question is worth 50 marks.
Write or type your answers on A4 paper, scan and save as a single PDF file
and upload to Canvas
Please make sure that your submission includes the following:
Your candidate number (Do not put your name on your paper)
The title of the module and the module code
Read Academic Integrity Statement
You MAY access online materials, notes etc. during this examination. You must complete
this assessment on your own and in your own words. DO NOT discuss this assessment with
others before the end of the 2.5 hour window. By submitting this assessment you confirm
that your assessment includes no instances of academic misconduct, for example plagiarism
or collusion. Any instance of academic misconduct will be thoroughly investigated in
accordance with our academic misconduct regulations.
CANDIDATE: please
attach Student Support
Unit sticker, if relevant.
2
G6077 Introduction to Computer Security
1. Cybercrime describes criminal activity in which computer systems or networks
are a tool, a target, or a place of criminal activity.

a) Illegal access, data interference, and misuse of devices are cybercrimes
cited in the convention on cybercrime. Indicate whether each one falls into
the types of computer crime categories listed above. Justify your answer.
[15 marks]
b) Consider a popular DRM system like Microsoft’s PlayReady, which
protects multimedia content streamed by a service such as Netflix to
a user’s computing device. Identify which company or person fulfils each
DRM component role illustrated in the figure below. Also, explain what is
happening at each one of the arrows.
[15 marks]
c) Consider a scenario where a company creates and patents a software.
Later, an individual creates and distributes similar software. Is this a
breach of intellectual property rights Justify your answer.
[10 marks]
d) Explain which approaches are required nowadays to protect privacy, given
that governmental and non-governmental organizations seek to learn as
much as possible about individuals.
[10 marks]
3
G6077 Introduction to Computer Security
2. Cryptographic data integrity algorithms are used in various security applications
and Internet protocols.

a) Alice sends a message with an attached hash value to Bob. How would
Bob know if there was a man-in-the-middle attack if the message digest
was sent in a secure fashion Justify your answer with an example.
[10 marks]
b) Regarding integrity, is using a hash function without encryption safe
Justify your answer.
[10 marks]
c) Consider the following statement: “Alice can use her private key and Bob’s
public key to achieve both secrecy and authentication when sending a
message to Bob”. Which key is used to achieve which goal
[10 marks]
d) What is the difference between a message authentication code and a one way hash function
[10 marks]
e) Consider the following statement: “Despite protecting two parties who
exchange messages from any third party, message authentication doesn’t
protect such parties against each other”. Explain this statement with some
concrete examples.
[10 marks]
/Turn over
4
G6077 Introduction to Computer Security
3. The appearance of quantum computers will soon threaten computer security
services and applications.
a) Quantum cryptography is concerned with the development of
cryptographic algorithms that are secure against the potential development
of quantum computers.
i. Is quantum computing a threat to all types of cryptographic
algorithms Justify your answer.
[10 marks]
ii. What is the most widely accepted alternative to existing
cryptographic algorithms, if any Justify your answer.
[15 marks]
iii. Are the cryptographic primitives used in Bitcoin safe against
quantum computers Justify your answer.
[15 marks]
b) Consider the following statement: “A policy may state that a given key may
no longer be used for encrypting new data”. Explain its meaning
considering the originator and recipient usage periods.
[10 marks]
End of paper