S T U D I O S PYQs INFORMATION SECURITY BTECH 3RD YEAR SHEET
Total No. of Printed Pages:3 Enrollment No...................................... Faculty of Science End Sem (Odd) Examination Dec-2018 CA3EL05 Information Security Programme: BCA Duration: 3 Hrs. Branch/Specialisation: Computer Application Maximum Marks: 60 Note: All questions are compulsory. Internal choices, if any, are indicated. Answers of Q.1 (MCQs) should be written in full instead of only a, b, c or d. Q.1 i. ii. iii. iv. v. vi. Output message in Cryptography is called (a) Plain text (b) Cipher Text (c) Plain and cipher (d) None of these Network security ensures: (a) Detecting attacks (b) Preventing attacks (c) Recovering attacks (d) All of these What is the largest disadvantage of the Symmetric Encryption? (a) More complex and therefore more time-consuming calculation. (b) Problem of the secure transmission of the Secret Key. (c) Less secure encryption function. (d) Isn’t used any more How many rounds does the AES-256 perform? (a) 10 (b) 12 (c) 14 (d) 16 For RSA to work, value of P must be less than value of (a) p (b) q (c) n (d) r In an efficient algorithm for factoring large number is discovered, which of the following schemes will be known to be not secure? (a) Diffie-Hellman (b) RSA (c) AES (d) None of these 1 1 1 1 1 1 P.T.O.
[2] vii. A digital signature is a (a) Bit string giving identity of a correspondent (b) A unique identification of a sender (c) An authentication of an electronic record by tying it uniquely to a key only a sender knows (d) An encrypted signature of a sender viii. A hashing function for digital signature I. Must give a hashed message which is shorter than the original message II. Must be hardware implementable III. Two different messages should not give the same hashed message IV. Is not essential for implementing digital signature (a) I and II (b) II and III (c) I and III (d) III and IV ix. CA Stands for: (a) Certified Auditing (b) Certification Authorities (c) Cyper Abuses (d) Certified Automation x. A firewall may be implemented in (a) Routers which connect intranet to internet (b) Bridges used in an intranet (c) Expensive modem (d) User’s application programs 1 OR OR Q.6 i. ii. iii. Explain the Diffie-Hellman key distribution scheme with suitable example. Perform encryption and decryption using the RSA algorithm, p=3; q=11; e=7; M=5 Explain Diffie-Hellman key exchange algorithm. Discuss about digital signature algorithm. Describe the basic concept of Kerberos. Attempt any two: What are web security threats? Give countermeasures of web security threats. Explain secure electronic transaction What are the types of firewalls? Explain any one type. 1 ****** 1 2 3 5 5 OR i. ii. iii. Write about strength of DES algorithm. Describe detailed general structure of DES. Explain with steps. Write down AES parameter and explain AES key expansion. 2 8 8 Q.4 i. What properties must a hash function have to be useful for message authentication? 3 Q.3 i. ii. iii. 1 What are threats in information security? Compare substitution ciphers with transposition ciphers What are the different types of active and passive attacks? Explain the model of network security. OR iii. Q.5 i. ii. iii. iv. Q.2 ii. 7 7 4 6 6 5 5 5
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Marking Scheme CA3EL05 Information Security Q.1 Q.2 i. Output message in Cryptography is called (b) Cipher Text ii. Network security ensures: (d) All of these iii. What is the largest disadvantage of the Symmetric Encryption? (b) Problem of the secure transmission of the Secret Key. iv. How many rounds does the AES-256 perform? (c) 14 v. For RSA to work, value of P must be less than value of (c) n vi. In an efficient algorithm for factoring large number is discovered, which of the following schemes will be known to be not secure? (b) RSA vii. A digital signature is a (c) An authentication of an electronic record by tying it uniquely to a key only a sender knows viii. A hashing function for digital signature I. Must give a hashed message which is shorter than the original message II. Must be hardware implementable III. Two different messages should not give the same hashed message IV. Is not essential for implementing digital signature (c) I and III ix. CA Stands for: (b) Certification Authorities x. A firewall may be implemented in (a) Routers which connect intranet to internet 1 i. 2 ii. iii. Any four types of threats in information security 0.5 mark each (0.5 mark * 4) Any three comparison substitution ciphers with transposition ciphers 1 mark for each (1 mark * 3) Types of active and passive attacks Definition of both 3 marks For example, of both 2 marks iv. Model Design of network security Explanation Q.3 i. Any for strength of DES algorithm 0.5 mark for each General structure of DES Proper explanation AES parameter AES key expansion. 1 1 ii. OR iii. Q.4 i. ii. OR iii. Q.5 i. 2 marks 3 marks 5 2 0.5 mark * 4) 4 marks 4 marks 3 marks 5 marks 8 8 1 1 1 1 1 ii. OR 1 iii. Q.6 i. 1 3 5 ii. iii. At least two properties 1.5 marks each (1.5 marks *2) Diffie-Hellman key distribution scheme with diagram 5 marks Example 2 marks Calculation of n =1 1 mark Calculation of f(n) = 1 1 mark Encryption 2.5 marks Decryption 2.5 marks 3 7 Diffie-Hellman key exchange algorithm. Formula and explanation Digital signature algorithm. Diagram Explanation Basic concept of Kerberos. Explanation with diagram 4 Attempt any two: Definition of web security threats Any three countermeasures of web security threats 1 mark for each Secure electronic transaction Types of firewalls 0.5 mark each (0.5 mark * 4) Explanation of any one type ****** 6 2 marks 4 marks 6 2 marks 5 3 marks 2 marks 3 marks 5 5
[2] Total No. of Printed Pages:2 Enrollment No...................................... x. A packet filter examins ____________ packets: (a) All (b) No (c) Some (d) Alternate 1 Q.2 i. 2 OR ii. iii. iv. Write any two security features we want to achieve in the cyber world. Explain Ceaser and modified Ceaser cipher technique. Explain Hill Cipher technique in detail. Explain the concept of Stagenography with a suitable example. i. ii. iii. Define block cipher with example. Explain the working of Data encryption Standard (DES) in detail. Explain the working of Advanced Encryption Standard (AES) in detail. 2 8 8 Q.4 i. ii. 3 7 OR iii. Explain the concept of public key cryptography. Explain the working of RSA Algorithm with suitable example in detail. Explain the working of Diffie Hellman Key Exchange in detail. Q.5 i. ii. iii. Explain the concept of Digital signatures in detail. Explain the working of MD5 algorithm in detail. Write short note on: (a) Authentication protocols (b) Message authentication codes 4 6 6 Faculty of Engineering End Sem (Odd) Examination Dec-2019 IT3EI08 Information Security Programme: B.Tech. Duration: 3 Hrs. Branch/Specialisation: IT Maximum Marks: 60 Note: All questions are compulsory. Internal choices, if any, are indicated. Answers of Q.1 (MCQs) should be written in full instead of only a, b, c or d. Q.1 i. Virus is a computer: 1 (a) File (b) Program (c) Database (d) Network ii. A worm ____________ modify a program: 1 (a) Does not (b) Does (c) May or may not (d) May iii. DES encrypts blocks of ____________ bits: 1 (a) 32 (b) 56 (c) 64 (d) 128 iv. There are around ____________ rounds in DES: 1 (a) 8 (b) 10 (c) 14 (d) 24 v. The private key ____________ 1 (a) Must be distributed (b) Must be shared with everyone. (c) Must be kept secret. (d) None of these vi. RSA ____________ be used for digital signatures: 1 (a) Must not (b) Cannot. (c) Can (d) Should not vii. ____________ is a message digest algorithm: 1 (a) DES (b) IDEA (c) MD5 (d) ASA viii. A ____________ is used to verify integrity of message: 1 (a) Message digest (b) Encryption Algorithm (c) Digital envelope (d) None of these ix. Kerberoes provides for ____________ be used for digital 1 signatures: (a) Encryption (b) SSO (c) Remote login (d) Local login P.T.O. Q.3 OR OR Q.6 i. ii. iii. Attempt any two: Explain the working of Pretty Good Privacy (PGP) in detail. Explain the working of Kerberoes in detail. Explain the working of Packet filter firewalls in detail. ****** 3 5 5 7 5 5 5
Theory with four points Marking Scheme IT3EI08 Information Security Q.1 Q.2 i. Virus is a computer: (b) Program ii. A worm ____________ modify a program: (b) Does iii. DES encrypts blocks of ____________ bits: (c) 64 iv. There are around ____________ rounds in DES: v. The private key ____________ (c) Must be kept secret. vi. RSA ____________ be used for digital signatures: (b) Cannot. vii. ____________ is a message digest algorithm: (c) MD5 viii. A ____________ is used to verify integrity of message: (a) Message digest ix. Kerberoes provides for ____________ be used for digital signatures: (b) SSO x. A packet filter examins ____________ packets: (a) All i. ii. iii. OR iv. Q.3 i. ii. OR iii. 1 i. 1 ii. 1 OR iii. 1 1 1 Q.5 1 i. ii. 1 OR iii. 1 1 Any two security features we want to achieve in the cyber world. 1 mark for each (1 mark * 2) Ceaser cipher technique 1.5 marks Modified Ceaser cipher technique 1.5 marks Hill Cipher technique Theory 2 marks Explanation 3 marks Concept of Stagenography 2 marks Example 3 marks 2 Block cipher Example Working of Data encryption Standard (DES) Diagram Theory Number of rounds Round function Working of Advanced Encryption Standard (AES) 2 1 mark 1 mark Q.4 Q.6 i. 3 ii. 5 iii. 5 8 3 marks 2 marks 1 mark 2 marks 8 Concept of public key cryptography Theory Diagram Working of RSA Algorithm Example Working of Diffie Hellman Key Exchange Theory Example Concept of Digital signatures Diagram Working of MD5 algorithm Theory Diagram Write short note on: (a) Authentication protocols Two protocols 1.5 marks for each (1.5 marks * 2) (b) Message authentication codes Formula Theory Attempt any two: Working of Pretty Good Privacy (PGP) Example Working of Kerberoes Diagram Theory Working of Packet filter firewalls Diagram Theory ****** 2 marks 6 marks 3 1.5 marks 1.5 marks 4 marks 3 marks 7 7 4 marks 3 marks 2 marks 2 marks 4 6 2 marks 4 marks 6 3 marks 1 mark 2 marks 4 marks 1 mark 5 5 2 marks 3 marks 5 2 marks 3 marks
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