rapidsnark

---

This library is Swift wrapper for the Rapidsnark. It enables the generation of proofs for specified circuits within an iOS environment.

Platform Support

iOS: Compatible with any iOS device with 64 bit architecture.

Version for emulator built without assembly optimizations, resulting in slower performance.

macOS: Not supported yet.

Requirements

• iOS 12.0+

Installation

rapidsnark is available through CocoaPods and SPM. To install it, simply add the following line to your Podfile:

pod 'rapidsnark'

or add it to your project SPM dependencies in XCode.

Usage

groth16ProveWithZKeyFilePath

Function takes path to .zkey file and witness file (as base64 encoded String) and returns proof and public signals.

Reads .zkey file directly from filesystem.

import rapidsnark

// ...

let zkeyPath = "path/to/zkey";
let wtns = PackageManager.default.contents(atPath: "path/to/wtns")?.base64EncodedString(options: .endLineWithLineFeed);

let (proof, publicSignals) = groth16ProveWithZKeyFilePath(zkeyPath, wtns);

groth16Verify

Verifies proof and public signals against verification key.

import rapidsnark

// ...

let zkey = PackageManager.default.contents(atPath: "path/to/zkey")?.base64EncodedString(options: .endLineWithLineFeed);
let wtns = PackageManager.default.contents(atPath: "path/to/wtns")?.base64EncodedString(options: .endLineWithLineFeed);
let verificationKey = PackageManager.default.contents(atPath: "path/to/verification_key")?.base64EncodedString(options: .endLineWithLineFeed);

let (proof, publicSignals) = await groth16Prove(zkey, wtns);

let proofValid = groth16Verify(proof, publicSignals, verificationKey);

groth16Prove

Function that takes zkey and witness files encoded as base64.

proof and publicSignals are base64 encoded strings.

Large circuits might cause OOM. Use with caution.

import rapidsnark

// ...

let zkey = PackageManager.default.contents(atPath: "path/to/zkey")?.base64EncodedString(options: .endLineWithLineFeed);
let wtns = PackageManager.default.contents(atPath: "path/to/wtns")?.base64EncodedString(options: .endLineWithLineFeed);

let (proof, publicSignals) = await groth16Prove(zkey, wtns);

groth16PublicSizeForZkeyFile

Calculates public buffer size for specified zkey.

import rapidsnark

// ...

let publicBufferSize = await groth16PublicSizeForZkeyFile("path/to/zkey");

Public buffer size

Both groth16Prove and groth16ProveWithZKeyFilePath has an optional proofBufferSize, publicBufferSize and errorBufferSize parameters. If publicBufferSize is too small it will be calculated automatically by library.

These parameters are used to set the size of the buffers used to store the proof, public signals and error.

If you have embedded circuit in the app, it is recommended to calculate the size of the public buffer once and reuse it. To calculate the size of public buffer call groth16PublicSizeForZkeyFile.

Example

To run the example project, clone the repo, and run pod install from the Example directory first. Then open the rapidsnark.xcworkspace file in XCode and run it on iOS device or simulator.

License

react-native-rapidsnark is part of the iden3 project 0KIMS association. Please check the COPYING file for more details.