How To Build A Flutter Chat App With End-to-end Encryption

Vigneshwar Published On March 20th, 2024 Tech Talks

Secure your real-time Flutter chat app with end-to-end encryption protocols. Allow only the sender and receiver to access the messages in a conversation.

When was the last time you sent a message to your family, friends, or colleagues? In less than a few hours, right? This is how frequently we are using chat apps these days. Be it WhatsApp, Microsoft Teams, Google Chat, or Signal, most quick conversations happen over messaging apps.

But, I’m sure there are times you hesitate to hit the ‘send’ button with thoughts like ‘Is it safe to send this message?’ or ‘Will anyone read my conversation?’.

Well, I get it! I had such a moment recently. Fortunately, I had the opportunity to do some interesting research on how chat apps are protected.

In this article, I will be sharing a few of the important points I’ve learned through my research.

I’ll cover:

1. How does your messaging app work?
2. What protects your conversations in a chat app?
3. How to develop a secure messaging app?

Now, it’s time we get into some interesting concepts about the messaging apps you use on your mobile or computers.

How Does Your Messaging App Work?

When you send a message to someone, your network (server) receives the message data and delivers it to the intended recipient. Now imagine, right at that moment, millions across the same network (server) send and receive messages. 

In other words, all our chat apps are connected to a server that transfers data between the sender and receiver. It is typically built on the client-server architecture. Above this, this server is capable of handling message transfers in real time.

This is why a message you send to someone on WhatsApp can be instantly read by the person at the other end of the chat. There is no delay, it’s just quick and instant!

While technology has improved so much to connect us right away, there is something that still prevails as a concern.

However, sometimes you face a hypothetical situation whether or not it is safe to exchange financial details, passwords and account credentials through chat.

And this is where end-to-end encryption comes into play.

 

Excited to Build an Encrypted Flutter Chat App?

Get Started

What Protects Your Conversations In A Chat App?

The process of protecting a message from third parties so that only the intended sender and recipient can access it is known as end-to-end encryption, or E2EE. By encrypting the message and storing it on the app’s server or database, E2EE offers security. You can also use the AES-GCM mode of operation to ensure authenticated encryption and integrity of your data.

Let me explain this in simple words.

• When you send a message ‘Hi Howdy’ from your chat app.
• A public encryption key encrypts the message into a non-readable message.
• The encrypted message reaches the server.
• The server receives this encrypted message and delivers it to the recipient device.
• Right at this point, the private encryption key decrypts the encrypted message to the original message ‘Hi Howdy’.
• And now, the recipient will be able to see this message on their device.

Now, there are 2 ways to do this practically:

1. If you are building your messaging application from scratch, by yourself, 

You can use Flutter Encrypt, a plugin for Flutter apps that enables developers to quickly and simply encrypt and securely store sensitive data. 

2. You can use a end-to-end encrypted Chat SDK

This is by far the most efficient way to secure user conversations in your Flutter chat app. You can simply integrate the SDK into your app, which comes with in-built security features.

If you are a developer and would like to build a secure chat app, I would totally recommend you to use a chat SDK that comes with built-in end-to-end encryption.

MirrorFly – The 100% End-to-Encrypted Chat SDK

The video, voice and chat SDKs built with MirrorFly come with built-in end-to-end encryption. Now, let me give you 6 reasons how this AES encryption will protect your app:

Strong Security: AES offers a high level of security that even government organizations, financial institutions and enterprises use this protocol to protect sensitive and confidential information. You can secure your Flutter messaging app to safeguard conversations at any time, anywhere. With just their email address and password, users can log in or register, and then use their unique Id to talk with their loved ones.

1. Protect all types of data: Whether it is text, files, and network traffic, AES helps you secure every data that is at rest and in transit.  
2. Best for instant messaging apps: In real time apps, the messages are exchanged instantly. AES protects them right away.
3. Fights back dangerous attacks: AES has withstood extensive cryptanalysis and is resistant to known cryptographic attacks. So, you can consider AES encrypted chat SDK for long-term security.
4. Industry regulations recommend AES: Many data protection regulations and standards, such as GDPR and HIPAA, recommend or require the use of strong encryption. And AES is often referred to as a suitable choice for compliance.
5. The new tech demands AES protection: Modern processors and hardware often include dedicated AES instruction sets, which can speed up encryption and decryption operations.
6. Tried and tested: AES has undergone rigorous scrutiny by the cryptographic community. It has proven resilient to various attacks. This gives us the confidence that it will protect our chat apps.

Decided to build an app with an End-to-end encrypted messaging app. 

Let me help you out. 

Steps To Build A Flutter App With End-to-Encrypted Chat SDK

Here is the full guide to build an app with messaging features using MirrorFly Flutter chat SDK. Let’s get started.

Requirements

• Android Lollipop 5.0 (API Level 21) or above
• Java 7 or higher
• Gradle 4.1.0 or higher The minimum requirements for Chat SDK for iOS
• iOS 12.1 or later

Get The License Key

Step 1: Sign-up for a MirrorFly account / Sign-in to your existing account.

Step 2: Go to the ‘Overview’ page.

Step 3: Navigate to the Application Info section and get your ‘License Key’.

Install UI Kit

Step 4: In your Android folder, add the following to your root build.gradle file.

allprojects {
 repositories {
 	google()
 	mavenCentral()
 	jcenter()
 	maven {
     	url "https://repo.mirrorfly.com/snapshot/"
 	}
 }
}

In the app/build.gradle file,  add the following dependencies.

android {
	packagingOptions {
 	exclude 'META-INF/AL2.0'
 	exclude 'META-INF/DEPENDENCIES'
 	exclude 'META-INF/LICENSE'
 	exclude 'META-INF/LICENSE.txt'
 	exclude 'META-INF/license.txt'
 	exclude 'META-INF/NOTICE'
 	exclude 'META-INF/NOTICE.txt'
 	exclude 'META-INF/notice.txt'
 	exclude 'META-INF/ASL2.0'
 	exclude 'META-INF/LGPL2.1'
 	exclude("META-INF/*.kotlin_module")
   }
}

Create iOS dependency

Step 5: Go to the end of your ios/Podfile and add the following code

post_install do |installer|
  installer.pods_project.targets.each do |target|
	flutter_additional_ios_build_settings(target)
	target.build_configurations.each do |config|
  	config.build_settings['IPHONEOS_DEPLOYMENT_TARGET'] = '12.1'
  	config.build_settings['ENABLE_BITCODE'] = 'NO'
  	config.build_settings['APPLICATION_EXTENSION_API_ONLY'] = 'No'
  	config.build_settings['BUILD_LIBRARY_FOR_DISTRIBUTION'] = 'YES'
  	config.build_settings["EXCLUDED_ARCHS[sdk=iphonesimulator*]"] = "arm64" 	 
 	end
  end
end

Step 6: Now, enable all the below-mentioned capabilities

Goto Project -> Target -> Signing & Capabilities -> Click + at the top left corner -> Search for the capabilities below

Create Flutter dependency

Step 7: In pubspec.yaml, add the below dependencies.

dependencies:
  mirrorfly_plugin: ^0.0.7

Step 8: In your project directory, run flutter pub get command .

import 'package:mirrorfly_plugin/mirrorfly.dart';

Initialize MirrorFly Plugin

• Place the below code in your main.dart file inside the main function before runApp() and initialize the plugin.

 void main() {
  WidgetsFlutterBinding.ensureInitialized();
  Mirrorfly.init(
  	baseUrl: 'https://api-preprod-sandbox.mirrorfly.com/api/v1/',
  	licenseKey: 'Your_Mirrorfly_Licence_Key',
  	iOSContainerID: 'Your_iOS_app_Group_id');
  runApp(const MyApp());
 }

Registration

• Register a user in sandbox Live mode using the code below.

Mirrorfly.registerUser(userIdentifier).then((value) {
  // you will get the user registration response
  var userData = registerModelFromJson(value);
}).catchError((error) {
	// Register user failed print throwable to find the exception details.
	debugPrint(error.message);
});

Send a One-to-One Message

• Enable your app to send messages with the below code:

var userJid = await Mirrorfly.getJid(username);

Mirrorfly.sendTextMessage(message, jid).then((value) {
  // you will get the message sent success response
  var chatMessage = sendMessageModelFromJson(value);
});

Receive a One-to-One Message

• Enable your app to receive messages with the below code:

Mirrorfly.onMessageReceived.listen(result){
  // you will get the new messages
  var chatMessage = sendMessageModelFromJson(result)
}

Conclusion

That’s it! That’s how you create a messaging app with an end-to-encrypted Flutter chat SDK. I’d like to insist once again that it is necessary whether you use an app or build an app, your chat app must be protected with these E2E protocols to make sure no conversation is eavesdropped. 

This article is only a glimpse of how MirrorFly can protect your messaging apps. Now, I’d recommend you the following as a next step:

1. Check out the documentation for a full-fledged idea of what other apps you could build. 
2. Talk to our experts if you are serious about building a safe chat app and need guidance.
3. Hire a dedicated developer to build a complete chat app for your business. 

Well, we’ve come to the end. For now, I’d bid my bye. Comment below if you have any queries or suggestions. Happy developing!

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