Important note

This is a new implementation of rapidsnark. The original (and now obsoleted) implemenation is available here: rapidsnark-old.

rapidsnark

Rapidsnark is a zkSnark proof generation written in C++ and intel/arm assembly. That generates proofs created in circom and snarkjs very fast.

Dependencies

You should have installed gcc, cmake, libsodium, and gmp (development)

In ubuntu:

sudo apt-get install build-essential cmake libgmp-dev libsodium-dev nasm curl m4

On MacOS:

brew install cmake gmp libsodium nasm

Compile prover in standalone mode

Compile prover for x86_64 host machine

git submodule init
git submodule update
./build_gmp.sh host
mkdir build_prover && cd build_prover
cmake .. -DCMAKE_BUILD_TYPE=Release -DCMAKE_INSTALL_PREFIX=../package
make -j4 && make install

Compile prover for macOS arm64 host machine

git submodule init
git submodule update
./build_gmp.sh macos_arm64
mkdir build_prover_macos_arm64 && cd build_prover_macos_arm64
cmake .. -DTARGET_PLATFORM=macos_arm64 -DCMAKE_BUILD_TYPE=Release -DCMAKE_INSTALL_PREFIX=../package_macos_arm64
make -j4 && make install

Compile prover for linux arm64 host machine

git submodule init
git submodule update
./build_gmp.sh host
mkdir build_prover && cd build_prover
cmake .. -DTARGET_PLATFORM=arm64_host -DCMAKE_BUILD_TYPE=Release -DCMAKE_INSTALL_PREFIX=../package
make -j4 && make install

Compile prover for linux arm64 machine

git submodule init
git submodule update
./build_gmp.sh host
mkdir build_prover && cd build_prover
cmake .. -DTARGET_PLATFORM=aarch64 -DCMAKE_BUILD_TYPE=Release -DCMAKE_INSTALL_PREFIX=../package_aarch64
make -j4 && make install

Compile prover for Android

Install Android NDK from https://developer.android.com/ndk or with help of "SDK Manager" in Android Studio.

Set the value of ANDROID_NDK environment variable to the absolute path of Android NDK root directory.

Examples:

export ANDROID_NDK=/home/test/Android/Sdk/ndk/23.1.7779620  # NDK is installed by "SDK Manager" in Android Studio.
export ANDROID_NDK=/home/test/android-ndk-r23b              # NDK is installed as a stand-alone package.

Prerequisites if build on Ubuntu:

apt-get install curl xz-utils build-essential cmake m4 nasm

Compilation:

git submodule init
git submodule update
./build_gmp.sh android
mkdir build_prover_android && cd build_prover_android
cmake .. -DTARGET_PLATFORM=ANDROID -DCMAKE_BUILD_TYPE=Release -DCMAKE_INSTALL_PREFIX=../package_android
make -j4 && make install

Compile prover for iOS

Install Xcode

git submodule init
git submodule update
./build_gmp.sh ios
mkdir build_prover_ios && cd build_prover_ios
cmake .. -GXcode -DTARGET_PLATFORM=IOS -DCMAKE_INSTALL_PREFIX=../package_ios
xcodebuild -destination 'generic/platform=iOS' -scheme rapidsnarkStatic -project rapidsnark.xcodeproj -configuration Release

Open generated Xcode project and compile prover.

Build for iOS emulator

Install Xcode

git submodule init
git submodule update
./build_gmp.sh ios_simulator
mkdir build_prover_ios_simulator && cd build_prover_ios_simulator
cmake .. -GXcode -DTARGET_PLATFORM=IOS -DCMAKE_INSTALL_PREFIX=../package_ios_simulator -DUSE_ASM=NO
xcodebuild -destination 'generic/platform=iOS Simulator' -scheme rapidsnarkStatic -project rapidsnark.xcodeproj

Files that you need to copy to your XCode project to link against Rapidsnark:

• build_prover_ios_simulator/src/Debug-iphonesimulator/librapidsnark.a
• build_prover_ios_simulator/src/Debug-iphonesimulator/libfq.a
• build_prover_ios_simulator/src/Debug-iphonesimulator/libfr.a
• depends/gmp/package_iphone_simulator/lib/libgmp.a

Building proof

You have a full prover compiled in the build directory.

So you can replace snarkjs command:

snarkjs groth16 prove <circuit.zkey> <witness.wtns> <proof.json> <public.json>

by this one

./package/bin/prover <circuit.zkey> <witness.wtns> <proof.json> <public.json>

Compile prover in server mode

npm install
git submodule init
git submodule update
npx task buildPistache
npx task buildProverServer

Launch prover in server mode

./build/proverServer  <port> <circuit1_zkey> <circuit2_zkey> ... <circuitN_zkey>

For every circuit.circom you have to generate with circom with --c option the circuit_cpp and after compilation you have to copy the executable into the build folder so the server can generate the witness and then the proof based on this witness. You have an example of the usage calling the server endpoints to generate the proof with Nodejs in /tools/request.js.

To test a request you should pass an input.json as a parameter to the request call.

node tools/request.js <input.json> <circuit>

Wrappers

Rapidsnark can be used with several programming languages and environments through wrappers that provide integration with the original library. Below is a list of available wrappers:

Wrapper	Repository Link
Go	https://github.com/iden3/go-rapidsnark
iOS	https://github.com/iden3/ios-rapidsnark
Android	https://github.com/iden3/android-rapidsnark
React Native	https://github.com/iden3/react-native-rapidsnark
Flutter	https://github.com/iden3/flutter-rapidsnark

Benchmark

This prover parallelizes as much as it can the proof generation.

The prover is much faster that snarkjs and faster than bellman.

[TODO] Some comparative tests should be done.

Run tests

You need to perform all the steps from the Compile prover in standalone mode section. After that you can run tests with the following command from the build directory:

# Make sure you are in the build directory
# ./build_prover for linux, ./build_prover_macos_arm64 for macOS.
cmake --build . --parallel && ctest --rerun-failed --output-on-failure

To run just the test_public_size test for custom zkey to measure the performance, you can run the following command from the build directory:

src/test_public_size ../testdata/circuit_final.zkey 86

License

rapidsnark is part of the iden3 project copyright 2021 0KIMS association and published with LGPL-3 license. Please check the COPYING file for more details.