辅导案例-COMP6211
NEW SECTION:
SECTION ID: COMP6211
This section contains questions pertaining to the material taught in
COMP6211 – Biometrics
This section contains 2 questions with the following QUESTION IDs:
 COMP6211_1
 COMP6211_2
Answer ALL questions
In your record of the answers, remember to record the CFA ID, the
SECTION ID, the QUESTION ID and YOUR ID at the top of EVERY
page and include a page number for your answers to assist in ordering.
Once you have completed the answers, produce and save an individual
PDF file for the answers to THIS SECTION ONLY.
To upload your file, follow the instructions at the start of this document.
Question COMP6211_1
It has been suggested that signals from the cardiovascular system can
be used in biometric authentication. The signals of particular interest
here derive from photoplethysmography (PPG), which refers to the use
of illumination-based sensors that are sensitive to volumetric changes as
blood travels through the body. Photoplethysmography sensors have
been developed for the fingertip and the ear lobe, and can provide a
convenient, noninvasive means of measuring heart rate and heart-rate
variability. Figure (Q1) shows Photoplethysmography signals from three
different subjects, obtained using a fingertip pulse oximeter. Different
individuals can exhibit significant differences in PPG signal morphology,
and these differences can be exploited for biometric authentication.
Figure (Q1) Photoplethysmography signals
[Sarkar, Abbott and Lynn, Proc. IEEE BTAS 2016]
Describe basic considerations of the nature of these signals and how
they could be used as a basis for a biometric system. Describe how the
signals could be transformed into feature vectors suitable for recognition,
and the process that would use these feature vectors for authentication
purposes.
[50 marks]
Question COMP6211_2
(a) Biometric authentication is largely based on interpreting measures
of distance. Describe how these distance measures can be
deployed to recognise or to authenticate people.
[15 marks]
(b) For sets of vector points = (1 ,2 ,3 , … ,) which have
mean values = (1, 2, 3,… , ) and covariance matrix Σ, the
Mahalanobis distance measure is defined as:
= √( − )Σ−1( − )
where the covariance matrix is formed of elements which express
the variance as
Σ = [( − )( − )]
where denotes the expected value.
For a system where there are three classes whose two
dimensional feature vectors are arranged with mean values (1,1),
(10,10) and (5,5) with variances (0.1,0.1), (1,1) and (2,2),
respectively, describe the possible result of recognition using the
Mahalanobis distance measure compared with than achieved
using the Euclidean distance.
[23 marks]
(c) Describe approaches that can be used to augment performance
when recognition within a biometric modality does not appear able
to achieve recognition.
[12 marks]
NEW SECTION:
SECTION ID: COMP6239
This section contains questions pertaining to the material taught in
COMP6239 – Mobile Applications Development
This section contains 2 questions with the following QUESTION IDs:
 COMP6239_1
 COMP6239_2
Answer ALL questions
In your record of the answers, remember to record the CFA ID, the
SECTION ID, the QUESTION ID and YOUR ID at the top of EVERY
page and include a page number for your answers to assist in ordering.
Once you have completed the answers, produce and save an individual
PDF file for the answers to THIS SECTION ONLY.
Follow the instructions on the rubric at the front of this document for
uploading.
Question COMP6239_1
Explain the various scenarios, based on different business needs that
you may face, and the kinds of development approaches you may
choose for your team to undertake. You are required to devise at least
four different scenarios. For each suggested development approach,
justify their suitability and consequences in terms of potential
advantages and disadvantages.
Hint: You can refer to lectures explaining the four different approaches to
mobile app development and the different reasons that a business may
require a mobile application.
[50 marks]
Question COMP6239_2
As part of the transformation to modern Android Apps, Google has
recently released Android Jetpack - a modern suite of architecture
guidelines, tools and libraries. Name the major components of this
modern suite and in each case briefly explain, in your view, the type of
effects it may have on the future of Android mobile applications.
[50 marks]


NEW SECTION:

SECTION ID: ELEC6242

This section contains questions pertaining to the material taught in

ELEC6242 – Cryptography

This section contains 2 questions with the following QUESTION IDs:

 ELEC6242_1
 ELEC6242_2

Answer ALL questions


In your record of the answers, remember to record the CFA ID, the
SECTION ID, the QUESTION ID and YOUR ID at the top of EVERY
page and include a page number for your answers to assist in ordering.

Once you have completed the answers, produce and save an individual
PDF file for the answers to THIS SECTION ONLY.

To upload your file, follow the instructions at the start of this document.







Question ELEC6242_1

(a) Explain the meaning of “Kirchhoff's Principle” and its relevance to
the design of modern ciphers.
[10 marks]

(b) Outline the principles of the cipher block chaining (CBC) mode of
operation, and explain the reasons behind its use.

[10 marks]

(c) Compression methods are typically used to prevent the use of data
redundancy in cryptanalysis. Calculate the theoretical maximum
compression ratio which can be achieved for the following
message (M2):

M2 = 1001111111
[10 marks]

(d) Steve has managed to intercept two of Bob‘s messages to Alice
(m1=33121, m2=16879) with their respective RSA digital
signatures (s1=42813, s2=39667). Explain with numerical
examples two methods that Steve may use to forge Bob’s
signature. It is assumed that the following parameters of the RSA
digital signature scheme used are known to Steve:
RSA modulus N=49163
The exponent of e=151
[20 marks]



Question ELEC6242_2

Let be the elliptic curve 2 = 3 + + 7 over the field F13=Z13
We regard as an Abelian group in the usual way.

(a) Explain the meaning of “group order” in number theory, then find
the order of the above group and indicate whether or not this is a
cyclic group.
[10 marks]

(b) Find an integer ≥ 0 such that

(11,6) = (2, 2) in

and explain your working in details
[10 marks]

(c) Find all pairs of points (P, Q) such that:

P + Q = 0

and explain your working in detail.
[10 marks]

(d) Alice has received the encrypted message {C1, C2} from Bob,
where:
C1= (2,2)
C2= 5
Explain in detail how to decrypt Alice’s message, assuming the
Elgamal encryption algorithm with the above group () was used to
encrypt it.

You are also given the following information
The generator point: G= (11,6)
Alice’s secret key: a=2
[20 marks]
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