prover

README

go-rapidsnark prover

A go wrapper for the RapidSNARK C++ library.

To use this module you either need to have RapidSNARK library available on your build host or have one of the supported architectures to use vendored pre-built libraries for convenience.

Dependencies

• C/C++ compiler and standard libraries available
• glibc version >= 2.31
• OpenMP

On Ubuntu it would be enough to install build-essential and libomp-dev packages.

If you build your project using golang Docker container, all tools are already installed.

To run compiled project on Alpine linux you would need to install there libstdc++, gcompat and libgomp packages.

Build using pre-built vendored RapidSNARK library.

For the following architectures, pre-built vendored libraries are included:

• MacOS x86_64
• MacOS ARM64 Apple Silicon
• Linux x86_64
• Linux ARM64 v8

Performance optimization on x86_64 hardware

Rapidsnark has optimization for recent x86_64 processors that gives ~2x speed boost, but older hardware may lack support for ADX and BMI2 instruction sets used.

MacOS build has it enabled. But for linux we disabled the optimization (at least for now, because GitHub Actions may use old hardware).

To enable optimization on linux use rapidsnark_asm build tag:

go build -tags rapidsnark_asm
go test -tags rapidsnark_asm

In the future we may change default behaviour, so to force disable optimizations use rapidsnark_noasm build tag.

Performance optimization on arm64 hardware

We used NEON instruction set, and it is always enabled, so no build tags are needed.

Build using custom RapidSNARK library.

You need gmp and rapidsnark libraries available on build host.

Supposed all needed files are in following directories:

• prover.h is located in ${HOME}/src/rapidsnark/src
• librapidsnark.a is located in ${HOME}/src/rapidsnark/build_prover/src
• libgmp.a is located in ${HOME}/src/rapidsnark/depends/gmp/package/lib

export CGO_CFLAGS="-I${HOME}/src/rapidsnark/src" 
export CGO_LDFLAGS="-L${HOME}/src/rapidsnark/build_prover/src -L${HOME}/src/rapidsnark/depends/gmp/package/lib"
go build -tags dynamic

Tag dynamic is required to exclude usage of vendored libraries.

Examples

Library usage example is available in /cmd/proof/ directory.

Documentation

Index

• Constants
• func Groth16Prover(zkey []byte, witness []byte) (proof *types.ZKProof, err error)
• func Groth16ProverRaw(zkey []byte, witness []byte) (proof string, publicInputs string, err error)

Constants

const MaxBufferSize = 10485760

Functions

func Groth16Prover

func Groth16Prover(zkey []byte,
	witness []byte) (proof *types.ZKProof, err error)

Groth16Prover generates proof and returns proof and pubsignals as types.ZKProof

func Groth16ProverRaw

func Groth16ProverRaw(zkey []byte,
	witness []byte) (proof string, publicInputs string, err error)

Groth16ProverRaw generates proof and returns proof and pubsignals as json string