# Cryptography And Network Security Assignment 3 Answers 2022

NPTEL Cryptography And Network Security Assignment 3 Answers 2022:- In this post, We have provided answers of NPTEL Cryptography And Network Security Assignment 3. We provided answers here only for reference. Plz, do your assignment at your own knowledge.

## NPTEL Cryptography And Network Security Assignment 3 Answers 2022 [July-Dec]

1. The solution of 7r = 2 (mod 11) is .

(a) 5
(b) 7
(c) 9
(d) 11

`Answer:- a`

2. The multiplicative inverse of 1234 mod 4321 is ______

(a) 1221
(b) 3239
(c) 3219
(d) 982

`Answer:- b`

3. Let (R, +,:) be a ring with two binary operations + (addition) and (multiplication). For a, b, c E R, a (b + c) = a c+b c is the representation for which property?

(a) Associative property.
(b) Distribution property.
(c) Commutative property.
(d) None of these.

`Answer:- b`

4. A group (G, *) (* is a binary operation) with commutative property is called….

(a) finite group.
(b) non-abelian group.
(c) abelian group.
(d) none of these.

`Answer:- c`

5. (Z10, +) is a cyclic group. The above statement is .

(a) True.
(b) False.

`Answer:- a`

6. (Z\ {0}, ) is a group if n =

(a) 10
(b) 11
(c) 4
(d) 6

`Answer:- b`

7. If a =a(mod m) and b = bi(mod m) then i) a +ba +bi(mod m) (i) a b E a1 bi(mod m) which of the following is true?

(a) (i) is true but (i) is false.
(b) 6) is false but (i) is true.
(c) both (i) & (ii) are true.
(d) both (i) & (ii) are false.

`Answer:- c`

8. The generator of the group (Z1o, +) is ..

(a) 2
(b) 3
(c) 5
(d) None of these.

`Answer:- b`

9. The order of 3 in the group (Zi3\ {0}, -) is .

(a) 3
(b) 10
(c) 11
(d) 12

`Answer:- a`

10. The solution of equation 7r +3=7 (mod 19) is..

(a) 7
(b) 6
(c)13
(d) 11

`Answer:- b`

## About Cryptography And Network Security

The aim of this course is to introduce the student to the areas of cryptography and cryptanalysis. This course develops a basic understanding of the algorithms used to protect users online and to understand some of the design choices behind these algorithms. Our aim is to develop a workable knowledge of the mathematics used in cryptology in this course. The course emphasizes giving a basic understanding of previous attacks on cryptosystems with the aim of preventing future attacks. A wide variety of basic cryptographic primitives will be discussed along with recent developments in some advanced topics like identity-based encryption, attribute-based encryption, functional encryption, two-party/multi-party computation, bitcoin and crypto-currency and postquantum cryptography. The cryptanalysis part will help us understand challenges for cybersecurity that includes network security, data security, mobile security, cloud security and endpoint security.

### COURSE LAYOUT

• Week 1: Introduction to cryptography, Classical Cryptosystem, Block Cipher.
• Week 2: Data Encryption Standard (DES), Triple DES, Modes of Operation, Stream Cipher.
• Week 3: LFSR-based Stream Cipher, Mathematical background, Abstract algebra, Number Theory.
• Week 4: Modular Inverse, Extended Euclid Algorithm, Fermat’s Little Theorem, Euler Phi-Function, Euler’s theorem.
• Week 5: Advanced Encryption Standard (AES), Introduction to Public Key Cryptosystem, Diffie-Hellman Key Exchange, Knapsack Cryptosystem, RSA Cryptosystem.
• Week 6: Primarily Testing, ElGamal Cryptosystem, Elliptic Curve over the Reals, Elliptic curve Modulo a Prime.
• Week 7: Generalized ElGamal Public Key Cryptosystem, Rabin Cryptosystem.
• Week 8: Message Authentication, Digital Signature, Key Management, Key Exchange, Hash Function.
• Week 9: Cryptographic Hash Function, Secure Hash Algorithm (SHA), Digital Signature Standard (DSS).
• Week 10: Cryptanalysis, Time-Memory Trade-off Attack, Differential and Linear Cryptanalysis.
• Week 11: Cryptanalysis on Stream Cipher, Modern Stream Ciphers, Shamir’s secret sharing and BE, Identity-based Encryption (IBE), Attribute-based Encryption (ABE).
• Week 12: Side-channel attack, The Secure Sockets Layer (SSL), Pretty Good Privacy (PGP), Introduction to Quantum Cryptography, Blockchain, Bitcoin and Cryptocurrency.

## CRITERIA TO GET A CERTIFICATE

Average assignment score = 25% of average of best 8 assignments out of the total 12 assignments given in the course.
Exam score = 75% of the proctored certification exam score out of 100

Final score = Average assignment score + Exam score

YOU WILL BE ELIGIBLE FOR A CERTIFICATE ONLY IF AVERAGE ASSIGNMENT SCORE >=10/25 AND EXAM SCORE >= 30/75. If one of the 2 criteria is not met, you will not get the certificate even if the Final score >= 40/100.