# NPTEL Blockchain and its Applications Assignment 2 Answers 2023

#### ByBrokenprogrammers

Feb 2, 2023

Hello Learners, In this Post, you will find NPTEL Blockchain and its Applications Assignment 2 Week 2 Answers 2023. All the Answers are provided below to help the students as a reference don’t straight away look for the solutions.

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## NPTEL Blockchain and its Applications Assignment 2 Answers 2023:

#### Q.1. Let Bob wants to send a long message to Alice. Alice should be able to confirm that it was indeed sent by Bob, and Bob later cannot deny that he had sent the message. They also want that nobody else should be able to see its content. Alice and Bob plan to use public key cryptography and cryptographic hashing techniques. Let the key pairs of Alice and Bob be (Pub A, Pri A) and (Pub B, Pri B), respectively.

Which of the following describes the correct order of steps to be used by Alice to send the digitally signed message. i. At Bob : M’ = E(M, KpubA) ii. At Alice : M = E(M’, Kpria) iii. Bob sends the message M’ to Alice iv. The signature along with the message is sent to Alice (M, M’) v. Bob : M’ = E(M, KpriB) vi. Signing the message with his private key : S = E(H(M), KpriB) vii. M = E(M’, KpubB)

• a. i, iii, ii, v, iv, vii, vi
• b. i, ii, iii, iv, v, vi, vii
• c. v, vii, ii, i, iii, iv, vi
• d. vii, vi, v, iv, iii, ii, i

• True
• False

#### Q.3. Which of the following is used to point a block in blockchain:

• a. Hash Pointer
• b. User ID
• c. Transaction ID
• d. Timestamp

#### Q.4. Suppose you have 6 data points — 1 to 6. The post-order traversal of the Merkle Tree is given by (here 8 means hash of 8, 43 means the combined hash of 4 and 3, and so on) :

• a. {12345656, 1234, 5656, 12, 34, 56, 56, 1, 2, 3, 4, 5, 6}
• b. {1, 12, 2, 3, 4, 34, 1234, 5, 6, 56, 123456}
• c. {1, 2, 12, 3, 4, 34, 1234, 5, 6, 56, 78, 5678, 12345678}
• d. {1, 2, 12, 3, 4, 34, 1234, 5, 6, 56, 56, 5656, 12345656}

#### Q.5.Which of the following is true for using a digital signature in blockchain?

• a. To check the validity of the source of a transactions
• b. None of the given options
• c. It will ensures that no one can deny of their own transaction
• d. It supports user authentication

#### Q.6. Which are the main Consensus Algorithms?

• a. Proof of Work
• b. Proof of Wager
• c. Proof of Stake
• d. Proof of Mining

#### Q.7. Why is consensus hard in asynchronous system?

I. No notion of global time II. faults in network III. nodes may crash/ faulty nodes

• a. II, III
• b. I, II
• c. I, III
• d. I, II, II

• True
• False

#### Q.9. Paxos consensus support(s) which of the below properties

• a. Liveliness
• b. Safety
• c. Both
• d. None of the above

#### Q.10.Which is/are true for Raft consensus?

• a. Crash Fault Tolerant
• b. Byzantine Fault Tolerant
• c. Both
• d. None of the above
##### NPTEL Blockchain and its Applications Assignment 2 Answers Join Group👇

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#### About NPTEL Blockchain and its Applications Course:

In the last few years, Blockchain technology has generated massive interest among governments, enterprises, and academics, because of its capability of providing a transparent, secured, tamper-proof solution for interconnecting different stakeholders in a trustless setup. In January 2021, the Ministry of Electronics and Information Technology (MeiTY), Government of India, published the first draft of the “National Strategy on Blockchain” that highlights 17 potential applications that are of national interest. Against this backdrop, this subject will cover the basic design principles of Blockchain technology and its applications over different sectors.

#### Course Layout:

• Week 1: Introduction to Blockchain Technology and its Importance
• Week 2: Basic Crypto Primitives I – Cryptographic Hash
• Week 3: Basic Crypto Primitives II – Digital Signature
• Week 4: Evolution of the Blockchain Technology
• Week 5: Elements of a Blockchain
• Week 6: Blockchain Consensus I – Permissionless Models
• Week 7: Blockchain Consensus II – Permissioned Models
• Week 8: Smart Contract Hands On I – Ethereum Smart Contracts (Permissionless Model)
• Week 9: Smart Contract Hand On II – Hyperledger Fabric (Permissioned Model)
• Week 10: Decentralized Identity Management
• Week 11: Blockchain Interoperability
• Week 12: Blockchain Applications
###### 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.

If you have not registered for exam kindly register Through https://examform.nptel.ac.in/