Blockchain and its Applications | Week 11

Session: JAN-APR 2024

Course Name: Blockchain and its Applications

Course Link: Click Here

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These are Blockchain and its Applications Assignment 11 Answers


Q1. If an attacker initially populates the victim node’s peer tables with attacker’s IP addresses in blockchain network, this attack is known as:
a. Sybil Attack
b. Eclipse Attack
с. Selfish Mining Attack
d. 51% Attack

Answer: b. Eclipse Attack


Q2. Which of the following can be used to identify a good blockchain use-case? (Mark multiple options if applied)
a. Participants
b. Assets
с. Transactions
d. Independent of everything

Answer: a, b, c


These are Blockchain and its Applications Assignment 11 Answers


Q3. Alice is performing an Eclipse Attack, and If her IP replaces another attacker IP, the evicted IP is resent and eventually replaced by honest IP. Is this a valid statement?
a. Yes
b. No

Answer: a. Yes


Q4. In a decentralized blockchain network, which scenario poses a significant risk known as the “51% Vulnerability”?
a. When a majority of users hold more than 51% of the cryptocurrency tokens.
b. When a single entity or a group controls more than 51% of the network’s computing power.
с. When more than 51% of the nodes in the network experience a temporary outage.
d. When more than 51% of the transactions in a block are invalid due to cryptographic errors.

Answer: b. When a single entity or a group controls more than 51% of the network’s computing power.


These are Blockchain and its Applications Assignment 11 Answers


Q5. Alice possesses 5 Bitcoins and initiates two separate transactions with the same Bitcoin. In which case does the double spending vulnerability occur?
a. Alice pays for a coffee and a book with the same 5 Bitcoins.
b. Alice accidentally sends 6 Bitcoins to a friend.
c. Alice sends 2 Bitcoins to one friend and 3 Bitcoins to another.
d. Alice checks her wallet balance but forgets to confirm the transaction.

See also  Blockchain and its Applications | Week 10

Answer: a. Alice pays for a coffee and a book with the same 5 Bitcoins.


Q6. In a selfish mining attack, discovering more blocks by pool develops a longer lead on the public chain, and continues to keep these new blocks _________________.
a. Private
b. Public

Answer: a. Private


These are Blockchain and its Applications Assignment 11 Answers


Q7. Which of the following scenarios is NOT a good use case for blockchain technology?
a. A supply chain network where participants require real-time visibility into the movement and origin of goods.
b. An online voting system aiming to enhance transparency, reduce fraud, and ensure the integrity of election results.
c. A centralized banking system seeking to improve transaction speed and reduce costs.
d. A healthcare system aiming to securely share patient records among different healthcare providers for better coordinated care.

Answer: c. A centralized banking system seeking to improve transaction speed and reduce costs.


Q8. What is a major problem with Proof Of Work?
a. It is difficult to implement
b. It is unreliable
c. Multiple miners have to be rewarded
d. It is CPU-intensive and consumes enormous amount of power.

Answer: d. It is CPU-intensive and consumes enormous amount of power.


These are Blockchain and its Applications Assignment 11 Answers


Q9. In Practical Byzantine Fault Tolerance, __________.
a. A master node selects the next node that adds the next block
b. The node with most coins is chosen for adding the next block
c. The nodes elect a leader and that leader adds the next block
d. None of the above

Answer: c. The nodes elect a leader and that leader adds the next block

See also  Blockchain and its Applications | Week 7

Q10. Alice places a bulk order for a cryptocurrency, and before it is processed, Bob, who is a miner, inserts his own buy order with a slightly higher price. In which case does the front-running attack occur?
a. Alice’s order is confirmed first due to network congestion.
b. Bob’s order is prioritized and confirmed ahead of Alice’s order.
c. Both Alice and Bob’s orders are cancelled due to conflicting transactions.
d. The network rejects both Alice and Bob’s orders, causing delays in confirmation.

Answer: b. Bob’s order is prioritized and confirmed ahead of Alice’s order.


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These are Blockchain and its Applications Assignment 11 Answers

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Session: JAN-APR 2022

Course Name: Blockchain and its Applications

Course Link: Click Here

These are Blockchain and its Applications Assignment 11 Answers


Q1. Hyperledger Aries is used for transmitting verifiable digital credentials.
a. False
b. True

Answer: b. True


Q2. Which of the following is true about Hypeledger Aries?
a. Aries cloud agent exposes API to access Aries capabilities
b. Aries controller implements application business logic
c. The controller sends requests
d. Response events are fed back to the controller as webhooks

Answer: a, b, c, d


These are Blockchain and its Applications Assignment 11 Answers


Q3. Which of the following is not a risk for blockchain operations?
a. 51% vulnerability
b. Private key security
c. Double spending
d. None of the above

Answer: d. None of the above

See also  Blockchain and its Applications | Week 3

Q4. Selfish mining attacks cause forking problems in the network.
a. True
b. False

Answer: a. True


These are Blockchain and its Applications Assignment 11 Answers


Q5. Which of the following is/are true for Eclipse Attack.
a. The Attacker partitions miners
b. The attacker re-populates the victim node’s peer tables
c. The victim node restarts and loses current outgoing connections
d. The victim establishes all new outgoing connections to attacker IP addresses

Answer: a, b, c, d


Q6. Attacker can perform a front-running attack if he/she knows about upcoming transactions?
a. False
b. True

Answer: b. True


These are Blockchain and its Applications Assignment 11 Answers


Q7. Blockchain Trust is mainly controlled by which of the following?
a. Consensus
b. Immutability
c. Provenance
d. Finality

Answer: a, b, c, d


Q8. For defining enterprise-level blockchain, which of the below factors need to be analyzed?
a. Network
b. People
c. Assets
d. Transactions

Answer: a, b, c, d


These are Blockchain and its Applications Assignment 11 Answers


Q9. In which of the following cases a node stops responding?
a. Power failure
b. Network failure
c. Security updates
d. DoS attacks

Answer: a, b, c, d


These are Blockchain and its Applications Assignment 11 Answers


Q10. What is a major problem with Proof of Work in a large-scale network?
a. It is difficult to implement
b. It is Resource-intensive and consumes enormous amounts of power
c. Multiple miners have to be rewarded
d. It is unreliable

Answer: b. It is Resource-intensive and consumes enormous amounts of power


These are Blockchain and its Applications Assignment 11 Answers

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These are Blockchain and its Applications Assignment 11 Answers