CS-802-A Block Chain Technologies - May 2024 Question Paper

Under each question, How to answer lists the points an answer should cover, outlined by CampusPrep from the syllabus. Check the details against your textbook.

1. 7 Marks
   aWhat are the key differences between public, private and consortium blockchains, and what are some use cases for each type?
   How to answer

   • Definition of public, private and consortium blockchains on access, control and consensus
   • Key differences on decentralization, permission, speed, security and trust
   • Use cases for each type with examples
2. 7 Marks
   bWhat are Merkle Tree? How importance are Merkle Tree in Blockchains.
   How to answer

   • Definition and structure of Merkle Tree with hashing
   • Construction of root from transactions
   • Importance for verification, integrity and scalability in blockchains
3. 7 Marks
   aWhat are some common validation techniques used in blockchain systems, such as proof-of-work and proof-of-stake?
   How to answer

   • Need for validation in decentralized systems
   • Proof-of-Work working, mining and difficulty
   • Proof-of-Stake working, validators, staking and comparison
4. 7 Marks
   bWhat is Double Spending? Is it possible to double spend in a Blockchain system.
   How to answer

   • Definition of double spending problem in digital cash
   • How blockchain prevents it via consensus, confirmations and UTXO
   • Possibility of double spend via 51%, race and Finney attacks
5. 7 Marks
   aWhat are some practical applications of Byzantine fault tolerant systems, and how are they used in industry?
   How to answer

   • Concept of Byzantine fault tolerance
   • Practical applications e.g. PBFT, supply chain, finance, IoT
   • Industrial use with examples like Hyperledger, Tendermint
6. 7 Marks
   bDiscuss design issues for permissioned blockchains and use cases.
   How to answer

   • Permissioned blockchain architecture and access control
   • Design issues: identity, privacy, scalability, governance
   • Use cases in enterprise, banking and healthcare
7. 7 Marks
   aHow do traditional cross-border payment methods differ from blockchain-based methods in terms of speed, cost and security?
   How to answer

   • Traditional cross-border flow via intermediaries, SWIFT
   • Comparison on speed, cost and settlement time
   • Comparison on security, transparency and fraud
8. 7 Marks
   bCompare HashCash PoW (Proof of Work) with Bitcoin PoW. Also discuss various types of attacks on PoW.
   How to answer

   • HashCash PoW origin and mechanism vs Bitcoin PoW with difficulty and mining
   • Comparison of purpose, difficulty adjustment and incentives
   • PoW attacks: 51%, selfish mining, Sybil, eclipse and race
9. 14 Marks
   Explain the following term:

   1. a)Byzantine algorithm
   2. b)Proof of Elapsed Time
   3. c)Digital signature
   How to answer

   • Byzantine algorithm definition and fault tolerance principle
   • Proof of Elapsed Time with Intel SGX and lottery
   • Digital signature working with keys, signing and verification
10. 7 Marks
    aWhat is Hyperledger Fabric and how does it differ from other blockchain platforms?
    How to answer

    • Hyperledger Fabric architecture: peers, orderers, channels, chaincode
    • Permissioned, modular and privacy features
    • Differences from public platforms like Bitcoin, Ethereum
11. 7 Marks
    bHow Bitcoin related with blockchain? Write the various steps of creation in Coins.
    How to answer

    • Bitcoin as first application of blockchain
    • Relation of transactions, blocks and mining
    • Steps of coin creation: transaction, mempool, mining, reward, confirmation
12. 7 Marks
    aWhich cryptographic algorithm used in Blockchain? Explain in detail.
    How to answer

    • Role of cryptography: hashing, signatures, Merkle
    • SHA-256, ECDSA, RIPEMD with use in addresses and blocks
    • Detailed working with example of transaction signing
13. 7 Marks
    bWhat is a smart contract and how is it used in the Ethereum blockchain?
    How to answer

    • Definition of smart contract as self-executing code
    • Ethereum EVM, Solidity and gas execution
    • Use cases with example of deployment and invocation
14. 14 Marks
    Explain the following term. (any three):

    1. a)Transaction validation
    2. b)Know your customer
    3. c)Crypto currency
    4. d)Creation of coin
    How to answer

    • Definition of each term with blockchain context
    • Key steps and entities involved
    • Importance with example for any three terms