The following guidance apply to all questions. Specific guidance to each question are given within
1. In all the questions, the marks are awarded for the quality of your discussion and
justification of your assumptions, choices, and conclusions.
2. You are expected to research your answers and to cite appropriate academic and/or other
sources; it is not sufficient to use only the module notes.
3. Each question has a specific page limit associated with it. Answers must not exceed the
indicated number of sides of A4 in each case. Page limits do not include any covering page,
visual aids (e.g., Figures and Tables), or the reference list. Excess pages will not be marked.
4. All references should be presented together at the end of your script.
5. The IEEE format of citation and referencing must be used.
6. For each major reference (say, the top 5 or so most used sources per question), a brief
explanation must be included (within the References section) as to why the reference is a
good-quality and credible source.
7. Appropriate use of visual aids is encouraged. They should be included to help the marker
understand the content.
8. The visual aids must be closely relevant to the text and act as complementary material to
make the material more reader-friendly. They must be of good quality and designed by the
student (not simply copied from other sources).
9. The visual aids must be appropriately labelled , explained and referenced within the text.
10. Abbreviations should be defined at first mention and used consistently thereafter.
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Q1 [30 Marks] Identification, Authentication & Authorisation (IAA) for
rented recording studio space
“MyStudio” is a new company which proposes to establish a new model for use of
recording studios. Instead of relying on human receptionists and sound engineers, they
propose to automate the process using AI for the sound engineering (customers will be
given a copy of the AI-mixed recording and a copy of the raw recording at the end of
their session), and automated systems to control access. To do this, they propose to
create a new “club” membership for customers.
They are also proposing to have some mobile studios, to be located at music festivals
etc., which will operate in the same way as their fixed locations. Communications
facilities in some of these temporary locations may be somewhat limited.
Club members need to be able to
a) book a studio at any time up to 1 hour before they need to use it, and allow up
to 7 band members or visitors (who do not need to be members of the club) to
join the club member during the time of the booking.
b) modify an existing booking to change the time of their booking or the amount
of space they wish to book.
c) render the booked space inaccessible to others if they need to leave the
premises during the booking period.
The company wants to ensure that
d) only active club members can use the system.
e) club members cannot “sub-let” booked space to non-members.
f) staff can gain access to any booked room at any time in order to check it is
being used in accordance with the club’s terms and conditions.
You have been asked to advise on identification and authentication features which
will allow the firm to ensure that only their club members will be able to make
bookings and access the facilities, in the ways described above, and to ensure that
the authorised club member is present while the room is occupied.
i. Cost effectiveness is an important criterion. Given the context (i.e., that the
system is for a subset of customers of a recording studio rental firm) identify the
four most important further criteria that you believe a suitable IAA system must
satisfy. [4 Marks]
ii. Provide an IAA system design and assess it against the five criteria identified in
(i) above. (Your system may use as many IAA mechanisms, in isolation or in
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combination, as you consider appropriate, but you must justify why each one is
used) [16 Marks]
iii. Provide an outline of how your system, above, could be adapted to cope with
guests (potential new club members), introduced by members of the club for
short periods. Guests will be permitted to use a studio which has been
assigned to a club member for the duration of the member’s booking, but only
that studio. The club member should be able to authorise a guest before the
club member arrives at the premises and should not have to accompany them
during their visit. Up to 4 guests, using the same studio, will be permitted per
Further Marking Guidance. Throughout, you should seek to provide justification for any choices
you make. You should quote from or refer to the literature to provide evidence of costs and
capabilities of particular approaches. Costs should not be restricted solely to equipment costs.
You must justify choices for the system context, i.e. for the context of the office space rental
company. This applies to your choice of initial criteria, and to the assessment of any proposed
system. Thus any system architecture and technologies deployed should be reasonable choices
based on plausible assessments of risk. (Your system must give value for money.) You can
assume that the rental company already has an appropriate system in place to deal with room
Your answer must not exceed 4 pages.
Q2 [20 marks] Reputation Management
The YorCy Cupcake Co. has been trading for about 3 years at food fairs and
markets around Yorkshire and has seen a substantial growth in sales and customer
loyalty. As the company is about to move into a new factory they are investigating
the potential for online sales and are aware that customer feedback can assist with
increasing sales. However, they have become aware that some online feedback
services (e.g. travel/hotel reviews) can result in a false impression being given. They
have asked for your assistance to design an online feedback system and to give
advice on how they can manage feedback posted on other review sites. Your
proposal should take the form of an initial report and must include :
i. [10 Marks] A scheme for ensuring that in-person (i.e. customers who purchase
from the company at food festivals/markets) and online customers can enter
their reviews and ratings into the system. Include in the report an analysis of
alternative options for this scheme, and a clear justification of the option you
ii. [ 10 Marks ] An analysis of the security threats
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a) to your proposal from part i of the question,
b) posed by other feedback/review sites
c) and the controls that can be used to mitigate these threats.
Your answer must not exceed 2 pages .
Q3 [26 Marks] BAN Logic and Protocol Correctness
Below are the assumptions and messages of a security protocol, expressed in BAN
The initial protocol assumptions:
The idealised protocol:
i) Describe briefly what the assumptions mean. [2 Marks]
ii) Using the inference rules of BAN logic, derive the goals achieved by the protocol.
Your solution must clearly state what inference rules are being applied to what
beliefs and what deductions are made at each step. [8 Marks]
iii) Explain informally what the protocol achieves. [3 Marks]
iv) Provide a standard notation description of the protocol and explain any actions
(e.g., checks) that the receiver of any message is expected to carry out. [6 Marks]
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v) Remove one assumption of your choice, such that the protocol cannot achieve
one or more goals. Demonstrate that using BAN logic. [4 Marks]
vi) Discuss briefly the main limitations of BAN logic. [3 Marks]
Further Marking Guidance. The level of detail provided in your BAN proof should be similar
to that demonstrated in class and in the classic paper “A Logic of Authentication” by
Burrows, Abadi, and Needham. In part (iv) you should remember that the BAN protocol
description is an abstract one and that a standard notation description need not follow the
structure of the abstract one exactly. Furthermore, there may be several correct designs
implementing the BAN description.
Your answer must not exceed 4 pages.
Q4 [24 marks] Delivering Packages by Drones
Consider a company that uses a system to deliver packages by drones. Customers
may order and pay for items online; then the company delivers these items to the
customer’s home address. Assume that you are a security engineer working at the
i) Identify potential adversaries and threats (as many as possible). [6 marks]
ii) Design an appropriate package delivery system considering both security and
efficiency. State any assumptions and trust models. [6 marks]
iii) Identify the risks associated with the above system and potential vulnerabilities. [6
iv) How can the above risks and vulnerabilities be mitigated? [6 marks]
Further Marking Guidance. You may use ideas from the literature (and elsewhere) but you
must cite all sources (and indicate the extent to which you have drawn own ideas). Some
degree of original thinking is expected.
Your answer must not exceed 4 pages.
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