Secure Link Messenger

Secure Link Messenger is a highly secure messaging application built with Flutter. It uses asymmetric encryption to ensure that messages are encrypted end-to-end, providing a high level of security and privacy for its users. This README will guide you through the features, installation process, and the technology stack used in the project.

Features

• End-to-End Encryption: Messages are encrypted on the sender's device and decrypted on the receiver's device, ensuring that only the intended recipient can read the messages.
• Asymmetric Encryption: Uses a pair of public and private keys to encrypt and decrypt messages.
• User Authentication: Users can register and log in using their email and password.
• Real-Time Messaging: Supports real-time messaging using Firebase Firestore.
• Secure Storage: User data and encryption keys are securely stored on the device.
• Cross-Platform: Available on both Android and iOS.

Screenshots

• SignIn Screen | SignUp Screen

• Chat List | Chat Screen

• Add To Contact | My Contacts

• User Screen

Technology Stack

• Flutter: The framework used to build the mobile application.
• Firebase: Backend-as-a-Service (BaaS) used for authentication, real-time database, and cloud storage.
• Asymmetric Encryption: Uses RSA for public-key cryptography.
• Flutter Bloc: State management library used for managing state across the application.

Installation

Prerequisites

• Flutter SDK: Install Flutter
• Firebase Project: Create a Firebase project

Steps

1. Clone the repository:

   git clone https://github.com/yourusername/secure-link-messenger.git

2. Set up Firebase:

   Go to the Firebase Console and create a new project. Add an Android and/or iOS app to your project. Download the google-services.json file for Android and place it in the android/app directory. Download the GoogleService-Info.plist file for iOS and place it in the ios/Runner directory. Enable Firebase Authentication and Firestore in your Firebase project.

3. Install dependencies:

   flutter pub get

4. Run the app:

   flutter run

Usage

Register and Login

• Users can register by providing an email and password.
• Upon successful registration, a pair of public and private keys is generated and stored securely.
• Users can log in using their registered email and password.

Sending and Receiving Messages

• Users can send messages to other registered users.
• Each message is encrypted using the recipient's public key.
• The recipient can decrypt the message using their private key.

Viewing Chats

• Users can view their chat list which displays the most recent message for each chat.
• Clicking on a chat opens the conversation where users can send and receive messages in real-time.

Security

• Public and Private Keys: Each user has a unique pair of public and private keys. The public key is used to encrypt messages, and the private key is used to decrypt messages.
• Secure Storage: Private keys are stored securely on the user's device using secure storage mechanisms provided by the platform.
• Firebase Authentication: Ensures that only authenticated users can access the application.