🔍 Crime Ledger : Crime Record Management Portal

A secure portal for police authorities to manage crime records, ensuring transparency and preventing unauthorized modifications or deletions.

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🚀 Features

✅ Add, view, and manage detailed crime records.
🔒 Immutable crime records to prevent tampering or deletion.
🕵️‍♂️ Detailed suspect profiles and case descriptions.
🔎 Search, filter, and sort crime records for efficient management.

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🛠 Technology Stack

🎨 Frontend: React.js
⚙️ Backend: Node.js (Express.js)
🗄 Database: MongoDB
⛓ Blockchain/Smart Contract: Solidity
🌍 Testnet: Ethereum Sepolia

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🏛 System Overview

The Criminal Report Management System consists of four main components:
1️⃣ Criminal Report Creation
2️⃣ Review by Senior Officer
3️⃣ Blockchain Integration
4️⃣ Validation

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📜 Process Flow

The following diagram illustrates the entire process from report creation to validation:

graph TD
    A[📝 Start] --> B[👮 Operational Officer Creates Report] 
B --> C[💾 Save Report to MongoDB] 
C --> D[🔍 Senior Officer Reviews Report] 
D --> E{✅ Approved?} 
E -->|Yes| I[🔗 Start Adding to Blockchain] 
E -->|No| G[🔄 Report will be reuploaded by Operational body] 
G --> H[🏁 End] 
 
I --> K[🔑 Hash Report Data] 
K --> M[🛡 Add Hash and MongoDB ID to Ethereum Blockchain] 

M --> H 
N[🔎 Validation Request] --> O[📂 Fetch Report from MongoDB] 
O --> P[🔢 Generate Hash of Fetched Data] 
P --> Q[🔗 Retrieve Blockchain Hash] 
Q --> R{⚖ Hashes Match?} 
R -->|Yes| S[✔ Data Validated] 
R -->|No| T[❌ Data Not Validated] 
S --> U[🏁 End] 
T --> U

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Local Setup Guide

Prerequisites

• Node.js (v16+)
• npm or yarn
• Metamask browser extension
• Ethereum wallet

Setup Steps

1. Alchemy RPC URL Setup

1. Go to Alchemy
2. Create a free account
3. Create a new app
4. Select "Ethereum" and "Sepolia" network
5. Copy the HTTP RPC URL

2. Metamask Installation

1. Install Metamask browser extension
2. Create a new wallet
3. Switch to Sepolia Testnet
   • Click network dropdown
   • Select "Add Network"
   • Choose "Ethereum Sepolia"

3. Private Key Configuration

1. In Metamask:
   • Click account menu
   • Select "Account Details"
   • Click "Export Private Key"
   • Enter wallet password
   • Copy private key

4. Sepolia Testnet Ethereum

1. Use Sepolia Faucets
2. Connect Metamask wallet
3. Request test ETH
4. Confirm transaction in Metamask

5. Project Configuration

# Clone repository
git clone [your-repo-url]
cd [project-directory]

# Install dependencies
npm install

# Create .env file
touch .env

# Add to .env
RPC_URL=your_alchemy_rpc_url
PRIVATE_KEY=your_metamask_private_key

6. Run Project

cd smart_contract
# Compile contracts
npx hardhat compile

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

Security Notes

• Never share private key
• Use testnet for development
• Store .env in .gitignore

After deployment

• copy the contract adress in the console
• view from sepolia blockchain explorer
• Get the mongo_uri from cloud
• Open the .env.example of server and fill the data by creating .env file
• Do "npm run dev" in both frontend and backend

Screenshots

• Home page
• Operational officer report submission form
• Extra pin security for Senior officer
• Dashboard for Senior officer