UNIT-V:USECASE MODEL – BLOCKCHAIN DIGITAL IDENTITY

 

Use Case 3: Blockchain for Government

Governments worldwide are adopting blockchain to enhance transparency, security, and efficiency in public services.

(i) Digital Identity, Land Records, and Government Record-Keeping

Traditional Challenges:

  • Identity theft & fraud: Paper-based or centralized identity systems are vulnerable.

  • Land record tampering: Corrupt officials can alter land ownership data.

  • Inefficiency: Paper-based records are slow, expensive, and prone to errors.

Blockchain Solution:
Self-Sovereign Digital Identity: Citizens control their own identity without relying on intermediaries.
Immutable Land Records: Once recorded, property ownership details cannot be changed fraudulently.
Inter-Government Data Sharing: Secure, permissioned blockchain networks enable real-time data exchange between agencies.

Examples:

  • Aadhaar Blockchain (India): Secure digital identity using blockchain.

  • Sweden’s Lantmäteriet: Uses blockchain for land registry and real estate transactions.

  • Dubai Land Department: Stores property transactions on Ethereum-based blockchain.

(ii) Public Distribution System & Social Welfare

Traditional Challenges:

  • Leakages & Corruption: Fake beneficiaries and ghost accounts cause fraud.

  • Lack of Transparency: Citizens don’t know how funds are distributed.

  • Delayed Payments: Bureaucratic inefficiencies slow down welfare disbursement.

Blockchain Solution:
Direct-to-Beneficiary Payments: Smart contracts ensure funds reach the right person instantly.
Tamper-Proof Distribution Records: Government agencies can track subsidies and aid distribution in real time.
Real-Time Auditing: Eliminates intermediaries and reduces corruption.

Examples:

  • World Food Programme (WFP) – “Building Blocks” (Jordan): Uses blockchain to distribute food aid to Syrian refugees.

  • Andhra Pradesh (India): Piloted blockchain for public distribution of food and benefits.

  • UK Welfare System (GovCoin): Tested blockchain-based universal credit payments.

Blockchain Cryptography, Privacy, and Security

Blockchain Cryptography

Blockchain security is built on cryptographic techniques that protect data integrity and privacy.

Key Cryptographic Methods Used in Blockchain:
Public-Private Key Cryptography (PKC):

  • Each user has a public key (visible to all) and a private key (kept secret).

  • Transactions are digitally signed using private keys.

  • Example: Bitcoin, Ethereum use ECDSA (Elliptic Curve Digital Signature Algorithm).

Hashing Algorithms:

  • Converts data into a unique fixed-length hash.

  • Prevents data tampering (e.g., SHA-256 in Bitcoin).

  • If any input changes, the hash output changes drastically.

Zero-Knowledge Proofs (ZKP):

  • Allows identity verification without revealing sensitive data.

  • Example: Zcash (Privacy-focused cryptocurrency).

Homomorphic Encryption:

  • Enables computations on encrypted data without decrypting it.

  • Used in privacy-preserving blockchain applications.

Privacy on Blockchain

Challenges:

  • Public blockchains store all transactions permanently.

  • Users need privacy for financial transactions and identity protection.

Privacy Solutions in Blockchain:
Private Blockchains: Only authorized users can access transaction data (e.g., Hyperledger Fabric).
Zero-Knowledge Proofs (ZKPs): Users can prove knowledge of information without revealing it.
Ring Signatures & Stealth Addresses: Used in Monero for anonymous transactions.
Mixing & CoinJoin: Breaks linkability between sender & receiver (used in Dash).

 Security on Blockchain

Potential Security Threats:

  • 51% Attack: A group controls 51% of the network’s computing power.

  • Smart Contract Vulnerabilities: Bugs in contract code can be exploited (e.g., DAO Hack on Ethereum).

  • Sybil Attack: A malicious actor creates multiple fake identities to manipulate consensus.

Security Measures:
Consensus Mechanisms: PoW, PoS, and PBFT prevent fraudulent transactions.
Formal Verification of Smart Contracts: Tools like Solidity static analysis detect security flaws.
Multi-Signature Wallets: Requires multiple approvals before executing transactions.

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