🔐 Secure Messenger (React + Spring Boot + PostgreSQL)

A secure chat application built with React (frontend), Spring Boot (backend), and PostgreSQL database.
Users can register, log in, select other users, and exchange encrypted messages in real-time.

---

✨ Features

• 🔑 User registration and login
• 🔐 AES-encrypted message storage
• 🗨️ Decrypted messages shown in the chat window
• 📧 User-to-user messaging interface
• 🔁 Auto-refreshing chat (polling)
• 🌐 CORS configured for secure frontend-backend communication
• ⚙️ Environment variables for deployment

---

🧰 Tech Stack

🖥️ Frontend (React)

• React
• Axios
• CSS (custom responsive UI)

🔧 Backend (Spring Boot)

• Java 17 + Spring Boot 3
• Spring Security + BCrypt
• Spring Data JPA
• PostgreSQL
• AES encryption (javax.crypto)
• Global CORS filter

---

🚀 Deployment

Component	Platform
Frontend	[Vercel]
Backend	[Render]
Database	PostgreSQL (Render)