Secure Encrypt/Decrypt Web Application

A full-stack web application for encrypting and decrypting confidential text messages using RSA asymmetric encryption with password-based access control.

Table of Contents

• Features
• Architecture
• Functional Requirements
• Non-Functional Requirements
• Technology Stack
• Installation
• Usage
• API Documentation
• Security
• Deployment
• Contributing
• License

Features

• 🔒 Text Encryption: Securely encrypt plaintext messages
• 🔓 Text Decryption: Decrypt messages with password authentication
• 📋 Copy to Clipboard: Easy copying of encrypted/decrypted results
• 📱 Responsive Design: Works on desktop, tablet, and mobile
• ⏰ Automatic Cleanup: Encrypted keys deleted after 3 days
• 🔒 Password Protection: No user accounts, password-based access

Architecture

C4 Diagrams

Context Diagram

@startuml
!include https://raw.githubusercontent.com/plantuml-stdlib/C4-PlantUML/master/C4_Context.puml

Person(user, "User", "Internet user wanting to encrypt/decrypt confidential text")
System(encryptDecryptApp, "Encrypt/Decrypt Web App", "Provides encryption/decryption utility with password-based access")

Rel(user, encryptDecryptApp, "Uses", "HTTPS")
@enduml

Container Diagram

@startuml
!include https://raw.githubusercontent.com/plantuml-stdlib/C4-PlantUML/master/C4_Container.puml

Person(user, "User", "Internet user")

System_Boundary(aws, "AWS Cloud") {
    Container(frontend, "React Frontend", "TypeScript, React", "Serves UI pages for encrypt/decrypt")
    Container(backend, "Quarkus Backend", "Java, Quarkus", "Handles encryption/decryption logic")
    ContainerDb(database, "DynamoDB", "NoSQL", "Stores encrypted private keys with TTL")
    Container(infra, "AWS Infrastructure", "CDK", "Manages Lambda, API Gateway, etc.")
}

Rel(user, frontend, "Uses", "HTTPS")
Rel(frontend, backend, "Makes API calls", "JSON/HTTPS")
Rel(backend, database, "Stores/Retrieves keys", "AWS SDK")
Rel(infra, backend, "Deploys", "CDK")
@enduml

Functional Requirements

Core Functionality

1. Encryption Process

   • User inputs plaintext message and password
   • System generates RSA key pair
   • Encrypts message with RSA public key
   • Encrypts private key with password-derived AES key
   • Stores encrypted private key in database with unique ID
   • Returns Base64-encoded encrypted message + ID

2. Decryption Process

   • User inputs encrypted message, ID, and password
   • System retrieves encrypted private key from database
   • Decrypts private key using password
   • Decrypts message with private key
   • Returns original plaintext

3. User Interface

   • Two-page application: Encrypt and Decrypt
   • Form validation and error handling
   • Loading states during API calls
   • Copy-to-clipboard functionality
   • Responsive design for all devices

Security Features

• Password-based authentication (no user accounts)
• Automatic key deletion after 3 days
• No sensitive data logging
• HTTPS encryption for all communications

Non-Functional Requirements

Performance

• Response Time: API responses < 2 seconds
• Concurrent Users: Support 100+ simultaneous users
• Scalability: Serverless architecture auto-scales

Security

• Encryption: RSA 2048-bit asymmetric encryption
• Data Protection: AES encryption for key storage
• Compliance: No personal data storage
• Audit: Secure logging without sensitive information

Usability

• Accessibility: WCAG 2.1 AA compliant
• Mobile Support: Responsive design for all screen sizes
• Intuitive UI: Clean, professional interface
• Error Handling: Clear error messages and recovery

Reliability

• Availability: 99.9% uptime target
• Data Integrity: Automatic key cleanup prevents data accumulation
• Error Recovery: Graceful handling of failures

Maintainability

• Code Quality: Well-documented, tested code
• Modularity: Separated concerns (frontend/backend/infrastructure)
• CI/CD: Automated testing and deployment

Technology Stack

Frontend

• React 18 with TypeScript
• Vite for build tooling
• Bootstrap 5 for responsive UI
• React Router for navigation
• Axios for HTTP requests

Backend

• Java 21 with Quarkus 3+
• Maven for dependency management
• AWS SDK for DynamoDB integration
• REST API with JSON communication

Infrastructure

• AWS Lambda for serverless compute
• API Gateway for REST API management
• DynamoDB for key storage with TTL
• S3 + CloudFront for static hosting
• AWS CDK for infrastructure as code

Development Tools

• Git for version control
• GitHub Actions for CI/CD
• Docker for local development
• DynamoDB Local for testing

Installation

Prerequisites

• Java 17+ (for backend)
• Node.js 18+ (for frontend)
• Docker (for local database)
• AWS CLI (for deployment)

Local Development Setup

1. Clone the repository

   git clone <repository-url>
   cd encryptdecrypt2

2. Backend Setup

   cd backend
   mvn clean install

3. Frontend Setup

   cd ../frontend
   npm install

4. Start Local Services

   # Start DynamoDB Local
   docker run -d -p 8000:8000 amazon/dynamodb-local
   
   # Start Backend
   cd ../backend
   mvn quarkus:dev
   
   # Start Frontend (new terminal)
   cd ../frontend
   npm run dev

5. Access Application

   • Frontend: http://localhost:5173
   • Backend API: http://localhost:8080

Usage

Encrypting a Message

1. Navigate to the Encrypt page
2. Enter your confidential message
3. Choose a strong password
4. Click "Encrypt Message"
5. Copy the encrypted result

Decrypting a Message

1. Navigate to the Decrypt page
2. Paste the encrypted message
3. Enter the password used for encryption
4. Click "Decrypt Message"
5. View the original message

API Documentation

POST /api/encrypt

Encrypt a plaintext message.

Request Body:

{
  "plaintext": "Your secret message",
  "password": "yourpassword"
}

Response:

{
  "encrypted": "BASE64_ENCODED_ENCRYPTED_DATA"
}

POST /api/decrypt

Decrypt an encrypted message.

Request Body:

{
  "encrypted": "BASE64_ENCODED_ENCRYPTED_DATA",
  "password": "yourpassword"
}

Response:

{
  "plaintext": "Your original message"
}

Security

Encryption Details

• Algorithm: RSA 2048-bit asymmetric encryption
• Key Management: Keys generated per encryption, stored encrypted
• Password Protection: PBKDF2 key derivation with AES encryption
• Data Lifecycle: Keys automatically deleted after 3 days

Best Practices

• Use strong, unique passwords
• Keep passwords secure (not shared)
• Encrypted data expires automatically
• No personal information stored

Deployment

AWS Deployment

1. Configure AWS Credentials

   aws configure

2. Deploy Infrastructure

   cd infra
   npm install
   npm run build
   cdk deploy

3. Deploy Application

   • GitHub Actions handles automated deployment
   • Frontend deployed to S3/CloudFront
   • Backend deployed to Lambda

Environment Variables

• AWS_REGION: AWS region
• DYNAMODB_TABLE: Table name for key storage
• CORS_ORIGIN: Frontend URL for CORS

Contributing

1. Fork the repository
2. Create a feature branch
3. Make your changes
4. Add tests
5. Submit a pull request

License

This project is licensed under the MIT License - see the LICENSE file for details.

Disclaimer

This application is provided "as is" for educational and utility purposes. While we strive for security, users should not rely on this for highly sensitive information without additional security measures. Always use strong passwords and understand that encrypted data is only as secure as your password.

The application does not store any personal information or user data. All encryption keys are temporary and automatically deleted.