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

Rajeshwari Published On December 18th, 2024 Tech Talks

Build and choose an encrypted Flutter chat app that creates a meaningful conversation pathway for only the senders and receivers with end-to-end encryption.

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 a messaging app work?
2. How does end-to-end encryption work in chat apps?
3. How to build a secure and encrypted Flutter chat app? (of course, I’ll add why Flutter)

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

How Does Your Chat App Work?

All the messaging/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. 

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.

Apart from the casual texts, sometimes you face a hypothetical situation regarding whether or not it is safe to exchange financial details, passwords, or account credentials through a chat app. 

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

 

Excited to Build an Encrypted Flutter Chat App?

Get Started

How does chat encryption work in messaging apps?

Before that let’s find the meaning of the encryption.

What is end-to-end encryption?

End-to-end encryption or E2EE is a security measure that protects your communication securely. With encryption, no one, including the messaging platform, can read the messages apart from the sender and receiver. In other words,

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’s see more about encryption with an example:

• 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.

How to implement end-to-end encryption chat?

Implementing end-to-end encryption is the most crucial step in building an encrypted messaging app. 

Let’s see the two easy steps to implement encryption in a messaging app:

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. 

You can use a end-to-end encrypted Flutter 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.

How to Build a Secure & Encrypted Flutter Chat App?

So, here we are: building a Flutter messaging app with custom message encryption can be done in two ways. You can develop from scratch or integrate an in-app chat API to enable messaging functionality. 

Before that let’s be clear: why Flutter?

Why Build a Chat App Using Flutter?

Flutter will be the best option for developers to build feature-packed and appealing mobile, web, and desktop applications. The versatile capability of the Flutter programming language makes it easy for developers to implement. 

Pros of Using Flutter in Your Encrypted Messaging App

• Cross Platform Compatibility: Flutter is best for cross-platform compatibility, allowing developers to create chat applications from a single database.
• Rapid Development Time: Implementing Flutter lets developers save development time and eliminate maintenance costs with a consistent user experience. 
• Extensive Library Set: Flutter offers pre-built library widgets for highly responsive chat UI that are easy to customize based on specific needs.

Let’s find the encrypted chat app tutorial. 

Let me help you out. 

Steps To Build A Flutter Chat 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)
}

MirrorFly Flutter SDK: 100% End-to-End Encrypted Messaging App

Since Flutter offers various flexibility and advanced functionalities, considering a chat SDK instead of developing from scratch can save a lot of time and cost. 

If you think about how secure and encrypted MirrorFly chat SDKs are, here are 6 reasons how AES encryption will protect your chat app. 

Strong Security: AES encryption and security offers a high level of security, and 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.

• 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.  
• Best for instant messaging apps: In real time apps, the messages are exchanged instantly. AES protects them right away.
• 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.
• 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.
• The new tech demands AES protection: Modern processors and hardware often include dedicated AES instruction sets, which can speed up encryption and decryption operations.
• 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 MirrorFly help you out. Contact the team for more information. Good Luck! 

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