Semaphore Flutter Package

This is a Flutter package for Semaphore protocol.

Getting Started

Follow these steps to integrate the Semaphore Flutter package into your project.

Adding a package dependency to an app

1. Add Dependency: You can add semaphore to your project using the command line or by manually editing pubspec.yaml.

   • Manual Edit (Required for local path or specific Git dependencies): Open your pubspec.yaml file and add semaphore under dependencies.

     dependencies:
         flutter:
             sdk: flutter
     
         semaphore:
             git:
                 url: https://github.com/zkmopro/semaphore_flutter.git

2. Install Package: Run the following command in your terminal from the root of your Flutter project:

   flutter pub get

Usage Example

Identity

import 'package:semaphore/semaphore.dart';

final privateKey = utf8.encode("secret");

final identity = Identity(privateKey);
final commitment = await identity.commitment();
final privateKey = await identity.privateKey();
final secretScalar = await identity.secretScalar();
final toElement = await identity.toElement();

Group

import 'package:semaphore/semaphore.dart';

final member1 = await identity1.toElement();
final member2 = await identity2.toElement();
final group = Group([member1, member2]);
// get root
await group.root();

Proof

import 'package:semaphore/semaphore.dart';

final message = "message";
final scope = "scope";
final treeDepth = 16;

final proof = await generateSemaphoreProof(
    identity,
    group,
    message,
    scope,
    treeDepth,
);

final valid = await verifySemaphoreProof(proof);

Flutter Example App

• Open the example app that uses the defined flutter package in the example/ folder

  cd example

• Install the dependencies

  flutter pub get

• Open an iOS simulator/device or an Android emulator/device and run the example app

  flutter run

• Clean the cache if you update the bindings and it throws errors

  flutter clean

How to Build the Package

iOS

• Follow the instructions in the mopro-swift-package README to build the package.

• Copy the bindings to the path ios/MoproiOSBindings.

• Then define the native module API in ios/Classes/SemaphorePlugin.swift to match the Flutter type. Please refer to Flutter - Data types support

Android

• Follow the instructions in the mopro-kotlin-package README to build the package.

• Copy the jniLibs folder to android/src/main/jniLibs and copy the uniffi folder to android/src/main/kotlin/uniffi

• Then define the native module API in android/src/main/kotlin/com/example/semaphore/SemaphorePlugin.kt to match the Flutter type. Please refer to Flutter - Data types support

Flutter Library

• Define Flutter's platform channel APIs to pass messages between Flutter and your desired platforms.
  • lib/semaphore_platform_interface.dart
  • lib/semaphore.dart
  • lib/semaphore_types.dart

Community

• X account:
• Telegram group:

Acknowledgements

This work was initially sponsored by a joint grant from PSE and 0xPARC. It is currently incubated by PSE.