KCS714 – Blockchain Architecture Design
B.Tech (SEM VII) – Theory Examination
Complete Solved Answers
SECTION A
(Attempt all questions in brief – 2 marks each)
a. Define distributed ledgers.
A distributed ledger is a digital database that is shared and synchronized across multiple nodes in a network. Each participant holds a copy of the ledger, and updates are recorded only after consensus, ensuring transparency, security, and immutability.
b. List the types of records present in the Blockchain database.
The main types of records in a blockchain database are:
Transaction records Block records
Smart contract records
c. Define the way to verify the accuracy of new transactions added to a Blockchain.
The accuracy of new transactions is verified through a consensus mechanism, where network nodes validate transactions using cryptographic techniques before adding them to a block.
d. List the general types of Blockchain.
The general types of blockchain are: Public blockchain
Private blockchain Consortium blockchain
Hybrid blockchain
e. Mention the key design features of Hyperledger Fabric model.
Key design features of Hyperledger Fabric include:
Permissioned network Modular architecture
Pluggable consensus mechanism Smart contracts (chaincode)
f. Differentiate between Blockchain and Hyperledger.
Blockchain is a broad technology concept mainly associated with public, permissionless networks like Bitcoin, while Hyperledger is a framework for building permissioned, enterprise-grade blockchain solutions.
g. List the features of Blockchain useful in financial services.
Blockchain features useful in financial services include:
Transparency Immutability
Decentralization Enhanced security
h. Describe how Blockchain eliminates problems associated with KYC.
Blockchain enables secure sharing of verified customer identity data among institutions, reducing duplication, cost, time, and fraud in the KYC process.
i. Name some use cases for Blockchain in identity management.
Some use cases are: Digital identity verification
E-governance services Secure login systems
Cross-border identity validation
j. Mention cryptographic algorithms used in Blockchain.
Common cryptographic algorithms used in blockchain are:
SHA-256 RSA
Elliptic Curve Cryptography (ECC) Hash functions
SECTION B
(Attempt any three – answers provided for all)
2(a). Explain the architecture of Blockchain. Also define blocks in Blockchain architecture.
Blockchain architecture consists of a decentralized network of nodes where each node maintains a copy of the ledger. The architecture includes data layer, network layer, consensus layer, and application layer.
A block is a data structure containing: Block header
Hash of previous block Timestamp
Merkle root List of transactions
Blocks are linked using cryptographic hashes, forming a secure chain.
2(b). Define the need for consensus mechanism and explain its types.
A consensus mechanism ensures agreement among distributed nodes about the validity of transactions. It prevents double spending and maintains trust.
Common consensus algorithms include: Proof of Work (PoW)
Proof of Stake (PoS) Practical Byzantine Fault Tolerance (PBFT)
Proof of Authority (PoA)
2(c). Define policy. Discuss policies needed in Hyperledger.
A policy defines rules that govern access, endorsement, and validation in a blockchain network.
Hyperledger Fabric policies include: Endorsement policy
Access control policy Lifecycle policy
Channel policy
These policies ensure security and controlled participation.
2(d). Discuss security and privacy issues in Blockchain.
Security issues include: 51% attack
Private key theft Smart contract vulnerabilities
Privacy issues include: Data transparency exposure
Transaction traceability
Solutions include encryption, permissioned networks, and privacy-enhancing protocols.
2(e). Explain how Blockchain uses cryptography to provide a trustless environment.
Blockchain uses cryptographic hash functions, digital signatures, and public-key cryptography to secure transactions. Trust is replaced by mathematical verification, eliminating the need for intermediaries.
SECTION C
3(a). Explain key Blockchain principles that eliminate security threats.
Blockchain principles such as decentralization, immutability, transparency, and cryptographic security reduce risks like data tampering, fraud, and unauthorized access.
3(b). Explain security and privacy protocols in Blockchain architecture.
Security protocols include: Public key infrastructure
Hashing Consensus algorithms
Privacy protocols include: Zero-knowledge proofs
Data encryption Permissioned access
4(a). Explain Merkle root and its implementation.
A Merkle root is a single hash representing all transactions in a block. Transactions are hashed pairwise repeatedly until one hash remains. It ensures data integrity and efficient verification.
4(b). Explain Proof of Work and differentiate PoW and PoS.
Proof of Work requires miners to solve complex mathematical problems.
Difference: PoW uses computation power
PoS uses stake ownership PoW is energy-intensive
PoS is energy-efficient
5(a). Describe Hyperledger Fabric and its key design features.
Hyperledger Fabric is an enterprise-grade permissioned blockchain framework. Features include modular design, smart contracts, identity management, and high scalability.
5(b). Briefly discuss Hyperledger Fabric architecture.
Architecture includes: Peers
Orderers Channels
Chaincode Membership Service Provider (MSP)
6(a). Blockchain application in financial systems with respect to KYC.
Blockchain simplifies KYC by allowing shared, verified customer data across banks, reducing duplication, cost, and fraud while improving compliance.
6(b). Problems in traditional supply chain and role of decentralization.
Traditional supply chains suffer from lack of transparency, fraud, delays, and data inconsistency. Blockchain decentralization improves traceability, trust, and efficiency.
7(a). Government adoption of Blockchain in healthcare and energy.
In healthcare, blockchain secures patient records. In energy management, it enables smart grids, transparent billing, and efficient resource tracking.
7(b). Role of Blockchain in government record keeping.
Blockchain ensures secure digital identity, tamper-proof land records, transparent public data, and efficient governance.
