🛡️ Sentinel Guard

Military-Grade Encrypted Desktop Vault

Sentinel Guard is a secure, standalone desktop application engineered to vault classified text documents. It features a multi-layered security architecture, including AES-256 envelope encryption, BCrypt cryptographic hashing, and a custom asynchronous UI designed to prevent unauthorized session access.

Lead Architect: Muhammad Hammad Saleem
Version: 1 (Production Build)

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🏗️ Core Architecture & Tech Stack

Component	Technology Used
Frontend GUI	Java Swing (AWT / Event Dispatch Thread)
Backend Engine	Java (JDK 8+)
Database	MySQL Relational Database
Cryptography	jBCrypt (Blowfish), javax.crypto (AES-256)
Build & Deployment	Apache Maven, Launch4j (Automated .exe generation)

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🔒 Security Protocols

Sentinel Guard operates on a "Zero Trust" model, ensuring that a compromised database does not result in compromised vault contents.

• Layer 1: BCrypt Hashing: User passwords are never stored in plaintext. They are salted and hashed using the BCrypt algorithm, neutralizing dictionary and rainbow-table attacks.
• Layer 2: Dual-Check Security Verification: Account recovery utilizes a custom security question. The answer is hashed, and the engine utilizes a custom Dual-Check protocol to account for case-sensitivity edge cases without compromising cryptographic integrity.
• Layer 3: Envelope Encryption: Each user is assigned a unique, dynamically generated Personal Master Key. This key is then encrypted using a system-wide AES-256 SYSTEM_KEY stored securely in a local .env file before being committed to the database.
• Layer 4: Idle Auto-Kill Timer: A global AWTEventListener tripwire monitors system-wide I/O events (mouse/keyboard). If a 5-minute idle threshold is breached, the engine violently terminates the session and purges active memory.

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💻 Asynchronous GUI Features

The user interface was built to mirror a high-security terminal, utilizing custom Java threading to prevent the Event Dispatch Thread (EDT) from freezing during complex operations.

• Matrix Typewriter Engine: Utilizes a javax.swing.Timer to asynchronously print classified vault documents letter-by-letter (15ms delay) without locking UI interactions.
• Airlock Boot Sequence: A dedicated loading interface that simulates cryptographic handshake sequences before granting vault access.
• Dynamic Component Routing: Employs a custom switchPanel architecture to cleanly destroy and instantiate UI memory blocks when moving between the Login, Vault, and Settings rooms.

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🚀 Deployment Pipeline

Sentinel Guard features a fully automated build pipeline. The application does not require manual file copying for deployment.

1. Clean the Factory: Run mvn clean to purge the old target cache.
2. Execute the Pipeline: Run mvn package.
3. Automated Wrapping: The launch4j-maven-plugin intercepts the Maven build phase, absorbs the "Fat JAR" (including all SQL and BCrypt dependencies), attaches the system .ico logo, and compiles a native Windows SentinelGuard.exe.

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⚙️ Setup & Installation (Developer Mode)

1. Ensure MySQL Server is running locally on port 3306.
2. Execute the provided database_setup.sql script to structure the users and notes tables.
3. Place your secure .env file containing the SYSTEM_KEY in the root deployment directory.
4. Run the executable to initiate the Sentinel protocol.