# HW3 - [20 Points 4 From Section 5.5 Do exercise 2 4 5 6[20...

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IS2150/TEL2810 Introduction to Security Homework 3 Total Points: 100 Due Date: September Oct 6, 2009 1) Do the exercises 1 and 2 from section 2.6; Do exercise 1 from section 3.5 [20 Points] 2) Exercise on Lattice [20 Points] Consider set of digits D = {1, 2, 3}. Let S be set of all numbers containing two digits from D ; i.e., each element a S can be written as a = a 1 a 2 where a 1 , a 2 D (i.e., they are elements of D ). For instance a = a 1 a 2 = 12 is an element of S , as a 1 = 1 and a 2 = 2. Let relation be the “ dominance relation on S . For every a, b S we say a is dominated by b (written as a   b ) if and only if a 1 b 1 and a 2 b 2 . (here is the “ less than or equal to ” relation on natural numbers 1, 2, and 3, i.e., 1 2, 2 3, 1 1, etc.) 1. Does relation generate a partial order or a total order on the elements of D ? Draw the Hasse diagram for the order it generates. 2. Does S and form a lattice? Explain. 3) From Section 4.8 Do exercise 3, 4, 5, 6
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Unformatted text preview: [20 Points] 4) From Section 5.5 Do exercise 2, 4, 5, 6 [20 Points] 5) Consider a Turing Machine with the following specification [20 Points] 1. Set of states: { k , k 1 , k 2 , k 3 } 2. Tape symbols: { A , B , C } 3. Final (or halting) state is k 3 4. Transition Functions: δ ( k , A ) = ( k 2 , C , R ); δ ( k 1 , C )= ( k 2 , B , R ); δ ( k 1 , A )= ( k 3 , C , L ); δ ( k 2 , A ) = ( k 1 , C , L ); δ ( k 2 , C ) = ( k 1 , B , R ) Assume your TM’s initial configuration is as shown below. 1. Show the mapping of the elements of this TM to a protection system. 2. Show all possible transitions, indicating each new TM configuration reached (i.e., state, head position and the symbols in each cell) and its corresponding protection state (the entries in the Access Control Matrix)....
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## This note was uploaded on 11/02/2009 for the course SIS 2150 taught by Professor Joshi during the Spring '09 term at Philadelphia.

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