B.E. Computers, IT Notes/Solved Question papers Maharashtra, Mumbai - Free call 022-66752917: Data compression and encryption

Showing posts with label Data compression and encryption. Show all posts

Saturday, August 2, 2014

DATA COMPRESSION AND ENCRYPTION (DCE) DECEMBER 2011 [ELECTIVE] ELECTRONICS AND TELECOMMUNICATION SEMESTER 7

Con. 6862-11. (REVISED COURSE) MP-5683
(3 Hours) [Total Marks : 100]

N. B. : (1) Question Number 1 is Compulsory.
(2) Attempt any four questions out of remaining six questions.

1. (a)	What is the need of compression.	5
(b)	Discuss the application of JPEG 2000.	5
(c)	Compare Cryptography and steganography.	5
(d)	What is Secure Electronic Payment System.	5
2. (a)	A source emits letter from an alphabet A= { a1, a2, a3, a4, a5) with	10
	probabilities P(a1) = 0.15 , P(a2) = 0.04 , P(a3) = 0.26 , P(a4) = 0.05
	and P(a5=0.05.
	a) Calculate the entropy of this source
	b) Find the Huffman code for this source.
	c) Find the average length of the code in
	d) and its redundancy.
(b)	Explain ADPCM Encoder and Decoder for audio compression	10
3. (a)	Describe the features of video compression as compared to image	10
	compression. Explain MPEG industry standards for video compression.
(b)	The o/p of the LZW encoder is the following sequence	5
	Decode the sequence.
(c)	Discuss in brief lossless audio compression	5
4. (a)	Explain the working of DES with block diagram	10
(b)	Discuss and explain security attacks on the system.	10
5. (a)	Explain algorithms for RSA using Chinese Remainder Theorom	10
(b)	Discuss Classical Encryption Techniques.	10
6. (a)	Explain Hash and MAC algorithms used for authentication.	10
(b)	Discuss certificate based and biometric system.	10
7.	Write short notes on any three :-	20
	(a) Approaches to Image Compression.
	(b) S-Box Design.
	(c) Digital signatures.
	(d) Performance and quality measures for compression.

Friday, August 1, 2014

DATA COMPRESSION AND ENCRYPTION (DCE) DECEMBER 2012 [ELECTIVE] ELECTRONICS AND TELECOMMUNICATION SEMESTER 7

DATA COMPRESSION AND ENCRYPTION (DCE) MAY 2012 [ELECTIVE] ELECTRONICS AND TELECOMMUNICATION SEMESTER 7

Con. 8490-12. KR-1980
(3 Hours) [Total Marks : 100]

N.B. : (1) Question No. 1 is Compulsory.
(2) Attempt any four questions out of remaining six questions.
(3) Assume suitable data if needed.
(4) Figures to be right indicates full marks.

1. (a)	Brief explain Modelling and coding with respect to data compression.	5
(b)	Explain the principle of Public Key Cryptography.	5
(c)	Explain the working principle of Arithmatic Coding with suitable example.	5
(d)	Expalin Chinese remainder theorem.	5
2. (a)	Define the following terms :-	10
	(i) Compression Ratio
	(ii) Distrotion
	(iii) Compression Rate
	(iv) Fidelity and Quality
	(v) Self information.
(b)	Explain Diffie - Hellman key exchange algorithm with example.	10
3. (a)	What is adaptive dictionary based coding. Explain any one method.	10
(b)	What is the signifiance of 'prime number' is public key cryptography ? Explain	10
	RSA algorithm with a suitable example.
4. (a)	Explain DPCM and ADPCM techniques used in audio compression.	10
(b)	What is Malicious Programe ? Explain different types of malicious programmes.	10
5. (a)	Explain audio encoder and decoder used in MPEG.	10
(b)	Explain Digital Immune System.	10
6. (a)	Design Huffman code for a source which generate letters from an alphabet.	10
	Also calculate entrophy of the source.
(b)	What is message digiest ? Explain HMAC algorithm.	10
7.	Write short notes on any two :-	20
	(a) JPEG 2000
	(b) Key Distribution Centre
	(c) Fire wall Design
	(d) Difference between :-
	(i) Lossy and Lossless compression
	(ii) Audio Compression and Image Compression.

DATA COMPRESSION AND ENCRYPTION (DCE) DECEMBER 2010 [ELECTIVE] ELECTRONICS AND TELECOMMUNICATION SEMESTER 7

Con.5656-10. (REVISED COURSE) GT-8910

(3 Hours) [Total Marks:-100]

N.B: (1) Question No.1 is compulsory.
(2) Attempt any four question out of remaining six questions.
(3) Assume suitable data wherever required.
(4) Figures to the right indicate full marks.

1. (a) What are the different measures of performance of data compression
techniques? [5 Marks]
(b) Discuss the drawbacks of statistical methods. [5 Marks]
(c) What is motion compression w.r.t Image Compression. [5 Marks]
(d) Discuss secure electronic payment system. [5 Marks]

2. (a) Distinguish between Scalar and Vector Quantization. Discuss the MPEG Audio Encoder
and Decoder systems. [10 Marks]
(b) Describe the features of Video Compression as compared to Image Compression. Explain
MPEG industry standard for Video Compression. [10 Marks]

3. (a) A source Emmits Letter's from alphabet A= {m, n, o, p, q} with probabilities p(m) = p(n) =
0.2, p(o) = 0.4, p(p) = p(q) = 0.1. [10 Marks]
(i) Calculate the entropy of the source.
(ii) Find Huffman Code using both the standard procedure and minimum variance method.
(iii) Find the average length of code and redundancy for each of the code of part (II).
(b) What are the different types of DES prevalent today? How is the security aspect maintained
in DES? [10 Marks]

4. (a) In which situation LZ 77 does the perform 'best' ? 'Worst'? Encode the string 'mnop mnopponm'
using LZ 78. What are the limitations of this method? [10 Marks]
(b) What are the main features of Digital Signature Standards. Suggest a suitable scheme for
secure communication between 'A' user and 'B' user covering issue of confidentiality and authentication. Justify your choice. [10 Marks]

5. (a) In high fidelity digital recording with a maximum frequency of 20 KHZ. The sampling rate
equals 44.1 KHz. How much memory is needed to store 1 hours of music if the number of
quantization level is:- [10 Marks]

(b) Explain the JPEG compression method used for Image Compression. How JPEG-LS is
different from JPEG? [10 Marks]

6. (a) What are the Active and Passive attacks on security of a system? How Chinese Remainder
Theorem use in security? [10 Marks]
(b) Discuss the certificate based and Bio-metric authentication. How does massage authentication
is different from the above. [10 Marks]

7. Write short note on(any two):- [20 Marks]
(a) "Frequency masking" and "Temporal Masking" w.r.t Audio Compression.
(b) "S" Box Design
(c) Diffie-e-Hellman Key Exchange
(d) Fire wall design

Thursday, July 31, 2014

DATA COMPRESSION AND ENCRYPTION (DCE) MAY 2010 [ELECTIVE] ELECTRONICS AND TELECOMMUNICATION SEMESTER 7

Con.3452-10. AN-2875.

(4 Hours) [Total Marks:-100]

N.B. (1) Question No.1 is compulsory.
(2) Attempt any four questions out of remaining six questions.

1. (a) Compare lossy and lossless compression techniques with suitable examples. [5 Marks]
(b) What are uniquely decodable codes? What are the tests performed to determine
them. [5 Marks]
(c) Compare the Arithmetic and Huffman coding. [5 Marks]
(d) What are the main features of digital signature? [5 Marks]

2. Consider a discrete memoryless source with probability {0.35, 0.25, 0.20, 0.15, 0.05}
Determine :- [20 Marks]
(i) Huffman code for this source.
(ii) Huffman code by minimum variance method.
(iii) Determine average length, entrophy and efficiency.
(iv) Draw binary root tree for both the codes.

3. (a) With S = {m, n, o, p} and p= {0.4, 0.3, 0.1, 0.2} encode message m n o p using
arithmetic code. Generate tag for encoding and also decipher the tag to decode the sequence
back. [10 Marks]
(b) Why is DCT more popular for image compression? Discuss its usage in JPEG. [10 Marks]

4. (a) Describe various standards of MPEG audio and video compressions. [10 Marks]
(b) Explain the role played by KDC in symmetric encryption. [10 Marks]

5. (a) Explain the working of DES with block diagram. [10 Marks]
(b) Explain Hash and MAC codes used for authentication. [10 Marks]

6. (a) Explain RSA algorithm with appropriate example. [10 Marks]
(b) Explain various key management techniques. [10 Marks]

7. Write short notes on any two:- [20 Marks]
(a) Chinese remainder theorem
(b) Run Length Coding.
(c) A law and law of companding.
(d) Text compression using PPM method.

DATA COMPRESSION AND ENCRYPTION (DCE) MAY 2012 [ELECTIVE] ELECTRONICS AND TELECOMMUNICATION SEMESTER 7

Con. 4636.12. (REVISED COURSE) GN-8942
(3 Hours) [Total Marks : 100]

N. B. : (1) Question No. 1 is Compulsory.
(2) Attempt any four questions out of remaining six questions.

1. (a)	What are the various models used for data compression?	5
(b)	Compare between A-Law and u-Law compression ?	5
(c)	What are active and passive attacts ?	5
(d)	What are is Biometric Authentication ? Explain with examples.	5
2. (a)	A source A= {a,b,c,d) has probabilities {0.7,0.15,0.1,0.05} respectively.	10
	Generate a tag for the sequence { a b c d a } using arithmetic code.
(b)	Explain working of DES.	10
3. (a)	Take an example and show the difference in the encoding procedures of LZ78	10
	and LZW.
(b)	Explain RSA algorithm with an example.	10
4. (a)	Discuss the various lossless techniques for image compression.	10
(b)	How are the keys distributed in conventional encryption systems ?	10
5. (a)	How is motion compensation used in video compression ?	10
(b)	What are digital signatures and how are they implemented ?	10
6. (a)	Why are Transforms used in compression ? How is JPEG different from	10
	JPEG2000 ?
(b)	What are the various aspects of a firewall design ?	10
7.	Write notes on (any two) :-	20
	(a) Chinese Remainder Theorom
	(b) Elliptic curve cryptography
	(c) MPEG audio standard
	(d) Steganography.

DATA COMPRESSION AND ENCRYPTION (DCE) DECEMBER 2009 [ELECTIVE] ELECTRONICS AND TELECOMMUNICATION SEMESTER 7

Con.5900-09. SP-6632

(3 Hours) [Total Marks:-100]

N.B:- (1) Question No.1 is compulsory.
(2) Attempt any four questions out of remaining six questions.

1. (a) Compare lossy and lossless compression. [5 Marks]
(b) Explain relative encoding for Fax and Telemetry. [5 Marks]
(c) Compare conventional and public key encryption. [5 Marks]
(d) Explain JPEG compression method for Image Compression. [5 Marks]

2. (a) What is data compression? Explain parameters to measure the performance of data
compression techniques. [10 Marks]
(b) Encode the following input stream using with and without move to front coding and compare
the average code word length for both coding methods. Assume alphabets
A=(a, b, c, d, m, n, o, p). Input stream 'C' = "abcddcbamnopponm". [10 Marks]

3. (a) Explain the Kraft Macmillan Inequality Criterion for variable size codes. Explain Ternary
and Canonical Huffman codes. [10 Marks]
(b) What is idea behind context based PPM algorithm? State the principle and how it can
achieve saving in terms of rates. Explain PPM method for text compression. [10 Marks]

4. (a) Explain the concepts of static and dynamic dictionary. Show the encoding with example
using LZ 77. [10 Marks]
(b) A source and its letters form an alphabet A=

with probabilities
P = {0.15, 0.06, 0.24, 0.05, 0.5} respectively. Calculate:- [10 Marks]
(i) Standard Huffman code.
(ii) Minimum Variance Huffman code.
(iii) Variance in both codes and compare them.
(iv) Average length and Redundancy of both the codes.
(v) Draw the binary code tree for both the codes and also prove that they are prefix codes.

5. (a) Explain various approaches for compassing images of various types. [10 Marks]
(b) Describe the features of video compression as compared to image compression. Explain
the MPEG industry standard for video compression. [10 Marks]

6. (a) Explain hybrid speech coders. In speech coding how the quality of speech can be improved
by using CELP and other sinusoidal coders over LPC. [10 Marks]
(b) Explain how key management and distribution is a problem and how it is solved. Explain the
various key management techniques. [10 Marks]

7. Write short notes on the following (any two):- [20 Marks]
(a) RSA algorithm
(b) HMAC design objectives and structures
(c) Data Encryption Standard Algorithms.

DATA COMPRESSION AND ENCRYPTION (DCE) May 2013 [ELECTIVE] ELECTRONICS AND TELECOMMUNICATION SEMESTER 7

DATA COMPRESSION AND ENCRYPTION (DCE) DECEMBER 2013 [ELECTIVE] ELECTRONICS AND TELECOMMUNICATION SEMESTER 7

Con. 9865-13. GS-6238
(3 Hours) [Total Marks : 100]

N.B. : (1) Question No. 1 is Compulsory.
(2) Attempt any four questions out of remaining six questions.
(3) Assume suitable data wherever required.
(4) Figures to be right indicates full marks.
(5) Answers to the question should be grouped and written together.

1. (a)	What are the different measures of performance of data compression techniques ?	5
(b)	Discuss the applicaltion of JPEG 2000.	5
(c)	Compare public and private key crypto-system.	5
(d)	What is secure electronic payment system ?	5
2. (a)	A source and its letter form an alphabet A = {a, b, c, d, e} with probabilities	10
	P = {0.15, 0.05, 0.25, 0.35, 0.2} respectively. Calculate :-
	(i) Standard Huffman code
	(ii) Minimum variance Huffman code
	(iii) Average length and redundancy of both codes
	(iv) Draw the binary code tree for both the codes.
(b)	Explain the working of DES with block diagram.	10
3. (a)	What are dictionary based compression schemes? Explain LZ77 with suitable examples.	10
(b)	What are various aspects of conventional encryption ? Discuss the types of attacks.	10
4. (a)	How are differential encoding schemes used in audio compression ?	10
(b)	Explain Chinese remainder theorem with an example.	10
5. (a)	Describe various approaches for Image Compression and discuss one of them in	10
	detail.
(b)	Explain Hash and MAC algorithm used for authenication.	10
6. (a)	Describe the features of Video Compression as compared to Image Compression.	10
	Explain MPEG industry standard for video compression.
(b)	Explain Digital Immune System.	10
7.	Write short notes on any two :-	20
	(a) Firewall design
	(b) Elliptic curve cryptography
	(c) MPEG audio standard
	(d) Two dimensional image transform.

DATA COMPRESSION AND ENCRYPTION (DCE) MAY 2009 [ELECTIVE] ELECTRONICS AND TELECOMMUNICATION SEMESTER 7

(3 Hours) [Total Marks:-100]

N.B:- (1) Question No.1 is compulsory.
(2) Attempt any four out of remaining six questions.

1. (a) Distinguish between Scalar and Vector quantization. [5 Marks]
(2) What is 'motion compensation' in video compression? [5 Marks]
(3) Compare symmetric and public key cryptography. [5 Marks]
(4) Classify security attacks and discuss them. [5 Marks]

2. (a) Draw the Adaptive Huffman tree for the string 'xyxwz'... Give the encoding and decoding
process for the same. [10 Marks]
(b) Explain the working of DES. [10 Marks]

3. (a) Encode the string 'mnop mnop ponm' using LZ78. What are the limitations of this method?
How does LZW overcome this limitations? [10 Marks]
(b) What is the significance of prime numbers in cryptography? Explain RSA algorithm with a
suitable example. [10 Marks]

4. (a) Describe various approaches for image compression and discuss one of them in
detail. [10 Marks]
(b) Explain the Diffie-hellman key exchange process. [10 Marks]

5. (a) Explain significance of modelling and coding with respect to data compression. Discuss the
various popular models used. [10 Marks]
(b) Discuss security of HASH and MAC functions. [10 marks]

6. (a) What are the various applications for the Run Length Encoding(RLE) compression
scheme? [10 Marks]
(b) What are the main features of Digital Signature? Discuss one if its algorithm. [10 Marks]

7. Write notes on any two:- [20 Marks]
(a) MPEG Audio
(b) Discrete Logarithm
(c) Stream Ciphers
(d) Arithmetic Coding

Wednesday, July 30, 2014

DATA COMPRESSION AND ENCRYPTION (DCE) DECEMBER 2013 [ELECTIVE] ELECTRONICS AND TELECOMMUNICATION SEMESTER 7

DATA COMPRESSION AND ENCRYPTION (DCE) [ELECTIVE] ELECTRONICS AND TELECOMMUNICATION SEMESTER 7

Con. 8446-13. LJ-14002
(3 Hours) [Total Marks : 100]

N. B. : (1) Question No. 1 is Compulsory.
(2) Attempt any four questions out of remaining six questions.

1. (a)	How are DPCM and ADPCM used for audio compression?	5
(b)	What is the difference between Shannon Fano coding and Huffman coding?	5
(c)	Discuss the major steps in S-box design.	5
(d)	What are digital signatures and how are they used?	5
2. (a)	A source A= {w,x,y,z) has probabilities {0.15,0.1,0.7,0.05} respectively. Generate	10
	and decipher the tag for the sequence [x,y,z,w,z] using arithmetic code.
(b)	Explain how triples DES works with two and three keys.	10
3. (a)	Take an alphabet string and code it using LZ78. what are the limitations and how can	10
	they be overcome with LZW?
(b)	Classify the different types of attacks and explain them with examples.	10
4. (a)	How is the frequency domain coding useful in audio compression?	10
(b)	Discuss the various principle involved in private and public key cryptography.	10
5. (a)	Explain one lossless technique of image compression.	10
(b)	What are message authentication and Hash function and how are they used?	10
6. (a)	What are the various steps involved in video compression?	10
(b)	Explain the various certificate based on Biometric authentication methods.	10
7.	Write short notes on (any two) :-	20
	(a) JPEG 2000.
	(b) Chinese Remainder Theorom.
	(c) Digital Immune Systems.
	(d) Success Electronic Payment Systems.