motemotech / nico_mopro

mopro

Making client-side proving on mobile simple (and fast).

Overview

• mopro-core - core mobile Rust library.
• mopro-ffi - wraps mopro-core and exposes UniFFI bindings.
• mopro-ios - iOS CocoaPod library exposing native Swift bindings.
• mopro-android - Android library exposing native Kotlin bindings.
• mopro-example-app - example iOS app using mopro-ios.
• ark-zkey - helper utility to make zkey more usable and faster in arkworks.

Architecture

The following illustration shows how mopro and its components fit together into the wider ZKP ecosystem:

Zooming in a bit:

How to use

Prepare circuits

• Install circom and snarkjs
• Run ./scripts/prepare.sh to check all prerequisites are set.

iOS

Prepare

• Install cocoapods

Build Bindings

To build bindings for iOS simulator debug mode, run

./scripts/build_ios.sh simulator debug

Open the mopro-ios/MoproKit/Example/MoproKit.xcworkspace in Xcode.

Update Bindings

To update bindings, run ./scripts/update_bindings.sh simulator|device debug|release.

• simulator is for building library to run on iOS simulator, device is for running on a real device
• debug is for Rust library to be in debug mode and release for release mode

Android

Prepare

• Install Android Studio
• Open Android Studio, and navigate to SDK Manager > SDK Tools > NDK (Side by Side) as laid out on the Android Developer site.
• Export $ANDROID_HOME and change {USER_NAME} to your username

  export ANDROID_HOME="/Users/{USER_NAME}/Library/Android/sdk"

• Locate which NDK version you have by

  ls $ANDROID_HOME/ndk
  # 26.1.10909125

  and set it to your NDK_PATH environment variable. e.g.

  NDK_PATH=$ANDROID_HOME/ndk/26.1.10909125

  Reference: Running Rust on Android with UniFFI

Build and Update Bindings

To build bindings for android simulator debug mode, run

./scripts/build_android.sh arm64 debug

• Device types: x86_64, x86, arm, arm64 Check your device architecture here: https://doc.e.foundation/devices For Android Studio simulator (Pixel series), choose arm64
• Mode: debug, release

Community and Talks

Join the Telegram group here.

Talk by @oskarth at ProgCrypto/Devconnect (Istanbul, November 2023): Slides (video pending)

Performance

Preliminary benchmarks on an iPhone 14 Max Pro:

• Keccak256 (150k constraints): 1.5s
  • ~x10-20 faster vs comparable circuit in browser
• anon-aadhaar / RSA Verify: ~6.5s
  • ~5s for witness generation (still in WASM), ~2s prover time
  • 80% of time on witness generation
  • ~x10 faster vs browser on phone
• Bottlenecks: loading zkey and wasm witness generation

Acknowledgements

This work is sponsored by a joint grant from PSE and 0xPARC.