5 [TURN OVER CST.2004.3.6 9 Introduction to Security (a) Explain briefly mechanisms that software on a desktop computer can use to securely generate secret keys for use in cryptographic protocols. [5 marks] (b) Give two different ways of implementing residual information protection in an operating system and explain the threat addressed by each. [5 marks] (c) Consider the standard POSIX file-system access control mechanism: (i) Under which conditions can files and subdirectories be removed from a parent directory? [2 marks] (ii) Many Unix variants implement an extension known as the "sticky bit". What is its function? [2 marks] (iii) On a POSIX system that lacks support for the "sticky bit", how could you achieve an equivalent effect? [2 marks] Give an illustration of how a coordinated curve xi xj can neglect to be bend predictable. Make sense of how this can be fixed. [2 marks] (d) Describe the AC-3 calculation for authorizing curve consistency. [5 marks] (e) Prove that the time intricacy of the AC-3 calculation is O(n 2d 3 ) where d is the size of the biggest space. [3 marks] (f ) Suggest a manner by which the idea of curve consistency, otherwise called 2-consistency can be stretched out to sets of three, instead of two factors. In the rest of the inquiry we will allude to this as 3-consistency. [1 mark] (g) Give an illustration of how a bunch of three factors could neglect to be 3-predictable, also, show how 3-consistency could then be forced. [2 marks] (h) Suggest a changed variant of the AC-3 calculation that can be utilized to uphold 3-consistency. Given a succession of focuses (Vi) n i=0 on a plane, consider the issue of introducing a smooth bend through every one of the places all together by building a succession of polynomial parametric capabilities, one for every span [Vi , Vi+1] n1 i=0 . (a) What is implied by Ck congruity at the intersection between two bend portions? [2 marks] (b) Explain how the level of the polynomial capability for a bend section obliges the progression at its two closures. What progression can be accomplished at each finish of a cubic fragment? [4 marks] (c) Derive a cubic parametric capability for the span [Vi , Vi+1] where 0 < I < n1. [10 marks] : Compose program to peruse a string and show its length (number of characters). in c+ : Compose program to peruse a letter and demonstrate whether the letter is 'a' or not. programing language is VB8 compose program to peruse in a string from the console and show the entire string in reverse (a) Describe the arrangements of the Data Protection Act. [8 marks] (b) You are planning and are going to send off a cell phone application which will look for to comprehend the profound state of the client, utilizing various information sources, for example, movement detecting, look acknowledgment, voice pressure estimation and the investigation of entered text. Its proclaimed intention is to empower administrations to communicate more empathically with clients. You propose to adapt it by serving promotions at times when the client is bound to purchase. Your "patrons" have raised a worry that this application will actually want to analyze misery, and that in outcome you might be putting away significant measures of delicate individual data.