Describe the purpose and four typical functions of a root kit.

You may use this reference for the question

[6 marks] 9 (TURN OVER) CST.2014.4.10 9 Security I Block ciphers usually process 64 or 128-bit blocks at a time. To illustrate how their modes of operation work, we can use instead a pseudo-random permutation that operates on the 26 letters of the English alphabet: 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 m A B C D E F G H I J K L M N O P Q R S T U V W X Y Z EK(m) P K X C Y W R S E J U D G O Z A T N M V F H L I B Q As the XOR operation is not defined on the set {A, . . . , Z}, we replace it here during encryption with modulo-26 addition (e.g., C D = F and Y C = A). (a) Encrypt the plaintext "TRIPOS" using: (i) electronic codebook mode; [2 marks] (ii) cipher-block chaining. On a POSIX system that lacks support for the "sticky bit", how could you achieve an equivalent effect? [2 marks] (d) VerySafe Ltd offer two vaults with electronic locks. They open only after the correct decimal code has been entered. Software Design #1: Costs $302,000, and will facilitate profits of $128,000/year Software Design #2: Costs $4210,000, and will facilitate profits of $129,500/year Which Software Design should they choose? Enter the NPV of the Software Design they should choose: Why do we learn Software Design Patterns? 3. (20015) What is a Software Design Pattern? stem to use demand paged virtual memory for efficiency. What problems could arise here, and how could they be overcome? [6 marks] 6 Numerical Analysis I (a) For Single Precision in the IEEE binary floating-point standard (IEEE 754) the precision is defined as 24, and the exponent requires 8 bits of storage. With reference to IEEE Single Precision, explain the terms exponent, significand, precision, sign bit, normalised number, denormal number. [6 marks] (b) Explain the term hidden bit. What are the values of the hidden bit for normalised and denormal numbers? Question: what number stable substance addressable recollections would you expect a completely

associated Hopfield network comprising of 100 neurons to be prepared to do

putting away? The retina is many times viewed as a picture catch gadget; however it has about

1100 million info sensors (photoreceptors) yet just 1 million result strands

(optic nerve axons). What are a ramifications of this 1100-to-1 proportion of

input channels to yield channels? [4 marks]. Provide some quantitative proof and contentions supporting the suggestion

that: "Availability is the essential computational standard in the cerebrum" (iii) How is the exponent stored and why? How are the exponent, significand and sign bit arranged in memory? [4 marks] (c) Let x denote the floating-point representation of a number x. Define the terms absolute error (x) and relative error (x) in representing x. How are x and x related? All its loads prepared and fixed, what three potential ways of behaving may

happen over the long haul in setup space as the net keeps on emphasizing in

reaction to a given info? [5 marks]

(ii.a) what number stable substance addressable recollections would you expect a completely

associated Hopfield network comprising of 100 neurons to be prepared to do

putting away? [5mark]

(iii.a) What property of those memory examples would make it generally plausible

that you could effectively prepare the organization to store the most extreme

number, and why? [5 marks] Give a brief and rudimentary clarification of the standards of how the language

coming about because of part (b.a) may be utilized to make a sentence structure analyser taking a

token stream as information (by means of calls to work lex()) and giving as result an

theoretical language structure tree relating to part (d.i). Summarize any issues connected with left-or right-cooperative administrators in the

two methods (in executing the parser and in developing the apparatus) you

illustrated to some degree (e.i). Notice both transcribed

also, consequently created grammar analysers.