About this previous year paper
BCS063 – BLOCKCHAIN ARCHITECTURE DESIGN
Time: 3 Hours | Max Marks: 70
SECTION A – Short Answer Questions
(2 × 7 = 14 marks | Attempt ALL)
Write definition + 1–2 clear points
a. Purpose of Cryptographic Hash Function in Blockchain
A cryptographic hash function converts input data into a fixed-length output.
It ensures data integrity, immutability, and tamper detection in blockchain blocks.
b. Any Two Blockchain Design Primitives
Cryptographic hash functions Digital signatures
(Other examples: Merkle trees, consensus mechanisms)
c. Two Scalability Challenges in Blockchain Limited transactions per second (TPS)
Increased latency due to consensus and block size limits
d. Two Major Limitations of Proof of Work (PoW)
Very high energy consumption Low scalability and slow transaction confirmation
e. Chaincode vs Traditional Smart Contracts
Chaincode (Hyperledger Fabric) runs in a permissioned environment, supports multiple languages, and follows an endorsement policy, unlike public blockchain smart contracts which are open and permissionless.
f. Blockchain for Traceability & Transparency in Supply Chain
Provides an immutable record of product movement Enables real-time tracking and reduces fraud
g. Digital Identity in Government: One Benefit & One Risk
Benefit: Secure and tamper-proof citizen records Risk: Privacy concerns if data governance is weak
SECTION B – Medium Answer Questions
(7 × 3 = 21 marks | Attempt ANY THREE)
Write concept → explanation → example
a. Basic Cryptographic Primitives in Blockchain
Hash functions: Data integrity Public-key cryptography: Authentication
Digital signatures: Transaction verification Example: SHA-256, RSA, ECDSA.
b. Permissioned Blockchain Consensus vs Public Blockchain
Permissioned blockchains use PBFT, Raft, or Kafka, which are faster, energy-efficient, and scalable compared to PoW-based public blockchains.
c. Chaincode Development & Deployment in Hyperledger Fabric
Steps: Write chaincode
Package chaincode Install on peers
Approve by organizations Commit to channel
Ensures controlled execution and validation.
d. Impact of Blockchain in Financial Services Faster settlement
Reduced intermediaries Improved transparency
Used in capital markets, insurance, and payments.
e. Blockchain in Government Infrastructure: Challenges & Solutions
Challenges: Scalability, legal framework, integration
Solutions: Permissioned networks, regulations, pilot projects
SECTION C – Attempt ANY ONE
(7 marks)
a. Evolution from Digital Currency to Blockchain
Digital currencies led to distributed ledgers to remove intermediaries.
Blockchain combined cryptography + consensus + decentralization, forming a secure transaction system.
b. Permissioned vs Permissionless Blockchain
| Permissioned | Permissionless |
|---|---|
| Controlled access | Open access |
| High performance | Low performance |
| Used in enterprises | Used in public crypto |