Digiverify

Government-Grade Trustless Land Registry & Multi-Sig Conveyance Suite

Next-generation digital land title tokenization, automated multi-signature escrow settlements, and tamper-proof judicial oversight on Ethereum Sepolia.

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Table of Contents

• Overview
• Key Features
• System Architecture & Lifecycle
• Smart Contract Ecosystem (Ethereum Sepolia)
• Technical Stack
• Project Structure
• Setup & Installation
  • Prerequisites
  • 1. Database Setup
  • 2. Smart Contract Deployment
  • 3. Backend Configuration & Execution
  • 4. Frontend Configuration & Execution
• API Overview
• Security & Compliance
• License

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Overview

Traditional land registry systems suffer from severe vulnerabilities: document forgery, fraudulent multiple sales of the same parcel, non-transparent bureaucratic delays, and slow judicial dispute resolution.

Digiverify solves these systemic problems by combining:

1. ERC-721 Property Tokenization on Ethereum Sepolia, minting immutable, sovereign digital land titles with cadastral boundaries.
2. ASBA-Style Bank Fund Blocking & Liens, locking buyer funds securely in escrow to prevent defaults and payment fraud.
3. Multi-Party Multi-Signature Settlement, requiring non-repudiable wallet signatures from the Seller, Buyer, Bank Admin, and Government Registrar before deed finalization.
4. Judicial Injunction & Dispute Protection, allowing legal authorities to freeze contested titles or reverse fraudulent transfers transparently on-chain.
5. Municipal Tax & Probate Governance, managing succession claims, inheritance transfers, and property tax clearances on-chain.
6. Decentralized IPFS Storage, securing deed documents and survey maps pinned via Pinata and immutably anchored on-chain.

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Key Features

• ERC-721 Digital Title Tokenization: Land ownership is minted as a non-fungible token containing unique government parcel identifiers, cadastral survey coordinates, and document hashes.
• 3-Party Multi-Signature Escrow: Enforces automated on-chain consensus where the Seller, Buyer, and Land Authority must each sign with cryptographic wallets before ownership transfers.
• ASBA-Style Bank Fund Blocking: Integrates banking fund-locking mechanisms that hold transaction funds in an account and guarantee payout only upon on-chain conveyance.
• Autonomous Title Conveyance: Zero manual sync needed — once all signatures and bank locks are in place, smart contracts finalize deed transfer atomically.
• Judicial Emergency Freeze & Injunction: Authorized court roles can freeze encumbered assets or execute judicial reversal orders with cryptographically verifiable case citations.
• Municipal Tax Vault & NOC: Tracks municipal valuations, records payments, and issues verifiable Tax Clearance NOCs directly on-chain.
• Inheritance & Succession Protocol: Formal probate workflows for legal heirs to stake inheritance claims with verification checkpoints.
• Soulbound Citizen Attestation: On-chain cryptographic identity attestation linking citizen KYC verification status.

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Smart Contract Ecosystem (Ethereum Sepolia)

The smart contract suite is written in Solidity 0.8.28, compiled with Hardhat, and deployed on the Ethereum Sepolia Testnet (Chain ID: 11155111).

Contract	Purpose	Sepolia Testnet Address	Explorer
LandNFT	ERC-721 token representing title deeds with metadata, freeze status, and restricted transfer logic.	0xbCB28DC4eF6242572c0a65D1643595C582106249	View on Etherscan
LandRegistry	Cadastral registry, survey verification workflows, and minting authorizations.	0xd6e6e94c053D204Ad535Ef8f2b01A1835696e9B1	View on Etherscan
SaleContract	Multi-sig escrow sales, ASBA lien verification, revenue collection, and automated conveyance.	0xA94321fA51b6F600Ef32Ab652965AC689D967b9B	View on Etherscan
CourtOverride	Judicial emergency module for freezing titles, cancelling fraudulent sales, and force-transfers.	0x4437904bF4cff91E91c16bB135752038d3418B8C	View on Etherscan
BankLienRegistry	Bank mortgage lien registry, collateralization checks, and encumbrance tracking.	0x6E8953f0288820bDB77CA89eaAF6c54Ff1250300	View on Etherscan
InheritanceSuccession	Probate claim submission, heir consensus, and court-authorized title succession.	0x712a073f1849456b13c983195a62fc79D50F52B8	View on Etherscan
PropertyTaxVault	Annual tax assessment registry, payment ledger, and cryptographic NOC clearance.	0x4bC7B4A62b7a97c40Bf4F028EbF043Fb0AbB7999	View on Etherscan
CitizenIdentityRegistry	Soulbound identity attestation for verified citizens and KYC level management.	0xCaa02E5ba741c314c12563dBE2eABCd2d6c5c6a3	View on Etherscan

• Network: Ethereum Sepolia Testnet
• Chain ID: 11155111
• Explorer: Sepolia Etherscan

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Technical Stack

Layer	Technologies	Description
Frontend	React 19, Vite, Tailwind CSS, Framer Motion, Lucide React	Modern, responsive SPA with role-specific dashboards, dark mode, and real-time status tracking.
Backend API	Node.js, Express 5, PostgreSQL (pg), JWT, bcrypt, Multer, Zod	High-performance REST API handling transactions, banking simulation, auth, and IPFS orchestration.
Smart Contracts	Solidity 0.8.28, OpenZeppelin v5, Hardhat, Ethers.js v6	8-contract modular suite with role-based access control, reentrancy guards, and multi-sig settlement.
Decentralized Storage	IPFS, Pinata API	Distributed storage for deed documents, land surveys, and tax receipts.
Security & Identity	AWS Rekognition, Web3 Signatures, SHA-256 Hashes, Rate Limiting	Biometric facial liveness matching, asymmetric ECDSA message verification, and anti-fraud filters.

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Project Structure

Digiverify/
├── backend/                 # Node.js Express 5 REST API
│   ├── blockchain/          # Ethers.js contract wrappers, ABIs & automated event listeners
│   ├── config/              # Database connection pool, blockchain config & SQL schema
│   ├── controllers/         # Business logic (Auth, Property, Sales, Bank, Admin, Biometric)
│   ├── middlewares/         # JWT verification, RBAC, rate limiting, file uploads
│   ├── models/              # PostgreSQL data access layer & query models
│   ├── routes/              # Express API route endpoints
│   ├── scripts/             # Administrative & synchronization CLI utilities
│   ├── services/            # IPFS pinning, sale workflow state machines, biometric matching
│   └── server.js            # Express application entry point
│
├── contracts/               # Hardhat Solidity Smart Contracts
│   ├── contracts/           # 8 Solidity smart contracts
│   ├── scripts/             # Deployment and test scripts
│   ├── hardhat.config.js    # Hardhat compiler & Sepolia network configuration
│   └── deployments.json     # Deployed contract addresses & deployment metadata
│
├── frontend/                # React 19 + Vite Web Application
│   ├── public/              # Static brand assets and icons
│   └── src/
│       ├── context/         # AuthContext, Web3Context
│       ├── layouts/         # AppLayout, AdminLayout, Sidebar layouts
│       ├── pages/
│       │   ├── Admin/       # Authority dashboards, KYC approval, revenue analytics, disputes
│       │   ├── Auth/        # Login, registration, biometric capture
│       │   └── Dashboard/   # Property management, purchase review, sales, fund blocking
│       └── services/        # Axios API clients & Web3 transaction helpers
│
└── model/                   # Machine learning risk scoring & anomaly detection API

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Setup & Installation

Prerequisites

• Node.js >= 18.x & npm >= 9.x
• PostgreSQL >= 14.x
• MetaMask browser extension configured for Ethereum Sepolia Testnet
• Testnet Sepolia ETH (from Google Cloud Web3 Faucet or Alchemy Faucet)

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1. Database Setup

1. Start your local PostgreSQL server.
2. Create the database:

   createdb digiverify

3. Initialize the database schema:

   psql -d digiverify -f backend/config/schema.sql

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2. Smart Contract Setup

The contracts are already compiled and deployed to Ethereum Sepolia. If you wish to recompile or redeploy:

cd contracts
npm install

# Compile contracts
npx hardhat compile

# Deploy to Ethereum Sepolia
npx hardhat run scripts/deploy.js --network sepolia

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3. Backend Configuration & Execution

1. Navigate to backend/ and install dependencies:

   cd backend
   npm install

2. Create .env from .env.example:

   cp .env.example .env

3. Configure your environment variables in .env:

   • Set PostgreSQL credentials (PGHOST, PGPORT, PGUSER, PGPASSWORD, PGDATABASE).
   • Set SEPOLIA_RPC_URL (e.g. from Alchemy or Infura).
   • Set SIGNER_PRIVATE_KEY for the backend authority wallet.
   • Set PINATA_API_KEY and PINATA_SECRET_API_KEY for IPFS uploads.

4. Start the backend server:

   npm run dev

   The backend API will start at http://localhost:5000.

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4. Frontend Configuration & Execution

1. Navigate to frontend/ and install dependencies:

   cd frontend
   npm install

2. Start the Vite development server:

   npm run dev

   The application will be accessible at http://localhost:5173.

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API Overview

Route Group	Path Prefix	Description
Authentication	/api/auth	User registration, login, wallet binding, JWT token renewal.
Properties	/api/properties	Property registration, survey approval, deed hashes, parcel search.
Sales & Escrow	/api/sales	Multi-sig sale initiation, buyer signing, automated final settlement.
Banking (ASBA)	/api/bank	Fund block creation, bank admin confirmation, lien status.
Biometrics	/api/biometric	Facial liveness detection, AWS Rekognition identity matching.
Admin & Authority	/api/admin	KYC attestation, survey review, dispute center, revenue analytics.
Risk & Analytics	/api/risk	ML-driven transaction risk scoring and anomaly detection.

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Security & Compliance

• Role-Based Access Control (RBAC): Smart contracts implement OpenZeppelin AccessControl segregation (DEFAULT_ADMIN_ROLE, AUTHORITY_ROLE, BANK_ROLE, COURT_ROLE).
• Cryptographic Multi-Signature Settlement: Eliminates unilateral transfers by requiring explicit on-chain authorizations from buyer, seller, bank, and regulatory authority.
• Automatic Fallback Reconciliation: The backend guarantees that database status and blockchain token ownership stay 100% consistent across all transactions.
• Cryptographic Document Integrity: Deed documents and boundary surveys are hashed with SHA-256 before upload and stored immutably on IPFS.
• Judicial Intervention: Protects against fraud and lost keys through designated court injunction and title deed force-transfer capabilities.

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License

This project is licensed under the Apache License, Version 2.0. See the LICENSE file for full details.

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_{Built by Team Desapphire}