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Information Theory and Coding : Question Paper Dec 2015 - Information Technology (Semester 4) | Mumbai University (MU)

## Information Theory and Coding - Dec 2015

### Information Technology (Semester 4)

TOTAL MARKS: 80
TOTAL TIME: 3 HOURS
(1) Question 1 is compulsory.
(2) Attempt any three from the remaining questions.
(3) Assume data if required.
(4) Figures to the right indicate full marks.
1 (a) Derive expression for entropy?(5 marks) 1 (b) What is lossless compression?(5 marks) 1 (c) List attacks threatening security goals.(5 marks) 1 (d) Explain the role of digital signature.(5 marks) 2 (a) Explain LZW compression algorithm with example.(10 marks) 2 (b) For DES symmetric algorithm, explain main steps involved showing block size, cipher key size and round key size.(10 marks) 3 (a) For (7, 4) cyclic code, find-out the generator matrix if G(D)=1+D+D3.(10 marks) 3 (b) Describe Huffman decoding procedure with example.(10 marks) 4 (a) Explain Diffie-Hellman algorithm. Which attack is it valnerable to?(10 marks) 4 (b) Describe convolution code in brief.(10 marks) 5 (a) State Fermat's Little Theorem with example and its applications.(10 marks) 5 (b) Describe lossy compression methods. Where we use lossy compression methods? How do we are it?(10 marks) 6 (a) Describe Chinese-Remainder Theorem and its applications.(10 marks) 6 (b) Define
i) Hamming distance
ii) Hamming Weight
iii) Syndrome
iv) Linear properties of code
v) Code rate
(10 marks)