- June 5, 2020

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]