142 lines
3.6 KiB
Markdown
142 lines
3.6 KiB
Markdown
|
# @T-Hax/websnark
|
||
|
|
|
||
|
|
This repository serves to configure the equivalent Tornado Cash repository for npm publishing. Below the rest of the description.
|
||
|
|
|
||
|
|
# websnark
|
||
|
|
|
||
|
|
A fast zkSnark proof generator written in native Web Assembly.
|
||
|
|
|
||
|
|
websnark is used to generate zkSnark Proofs from the browser.
|
||
|
|
|
||
|
|
This module generates highly optimized Web Assembly modules for the low level
|
||
|
|
cryptographic primitives.
|
||
|
|
|
||
|
|
It also makes use of the Web Workers feature to parallelize the generation
|
||
|
|
of the zero knoledge proofs.
|
||
|
|
|
||
|
|
The result is a fast library with times close to libsnarks but fully compatible for
|
||
|
|
browsers.
|
||
|
|
|
||
|
|
## Usage
|
||
|
|
|
||
|
|
You just need to import the websnark.js found in the build directory.
|
||
|
|
|
||
|
|
```html
|
||
|
|
<script src="websnark.js" />
|
||
|
|
```
|
||
|
|
|
||
|
|
This library has a single javascript function:
|
||
|
|
|
||
|
|
genZKSnarkProof(witness, provingKey, cb)
|
||
|
|
|
||
|
|
cb is the callback. If cb is undefined, then the function will return a promise.
|
||
|
|
|
||
|
|
witness is a binary buffer with all the signals in binnary format. The buffer is packt in 32bytes Little Endian Encoded Field Elements.
|
||
|
|
|
||
|
|
You can use the tool to build the binary file from the witness.json file generated by [snarkjs](https://github.com/iden3/snarkjs).
|
||
|
|
|
||
|
|
### IMPORTANT: Please be sure you run your setup with `--protocol groth` websnark only generates groth16 proofs!
|
||
|
|
|
||
|
|
```
|
||
|
|
node ../tools/buildwitness.js -i witness.json -o witness.bin
|
||
|
|
```
|
||
|
|
|
||
|
|
provingKey is the binary buffer with the binary representation of the proving key.
|
||
|
|
|
||
|
|
Check the tool tools/buildpkey.js to convert a proving_key.json file generated
|
||
|
|
in [snarkjs](https://github.com/iden3/snarkjs) to a proving_key.bin file that can
|
||
|
|
be used directly with this library.
|
||
|
|
|
||
|
|
```
|
||
|
|
node ../tools/buildpkey.js -i proving_key.json -o proving_key.bin
|
||
|
|
```
|
||
|
|
|
||
|
|
The result is a JSON object with pi_a, pi_b and pi_c points.
|
||
|
|
|
||
|
|
You can use the stringified version of this JSON as a proof.json in [snarkjs](https://github.com/iden3/snarkjs)
|
||
|
|
|
||
|
|
|
||
|
|
Here is a simple example of a web page that loads a key and a witness and generates the proof when the button is pressed.
|
||
|
|
|
||
|
|
```html
|
||
|
|
<html>
|
||
|
|
<header>
|
||
|
|
</header>
|
||
|
|
<script src="websnark.js"></script>
|
||
|
|
<script>
|
||
|
|
|
||
|
|
var witness;
|
||
|
|
var proving_key;
|
||
|
|
|
||
|
|
function onLoad() {
|
||
|
|
|
||
|
|
fetch("proving_key.bin").then( (response) => {
|
||
|
|
return response.arrayBuffer();
|
||
|
|
}).then( (b) => {
|
||
|
|
provingKey = b;
|
||
|
|
});
|
||
|
|
|
||
|
|
fetch("witness.bin").then( (response) => {
|
||
|
|
return response.arrayBuffer();
|
||
|
|
}).then( (b) => {
|
||
|
|
witness = b;
|
||
|
|
});
|
||
|
|
}
|
||
|
|
|
||
|
|
function calcProof() {
|
||
|
|
const start = new Date().getTime();
|
||
|
|
document.getElementById("time").innerHTML = "processing....";
|
||
|
|
document.getElementById("proof").innerHTML = "";
|
||
|
|
|
||
|
|
window.genZKSnarkProof(witness, provingKey).then((p)=> {
|
||
|
|
const end = new Date().getTime();
|
||
|
|
const time = end - start;
|
||
|
|
document.getElementById("time").innerHTML = `Time to compute: ${time}ms`;
|
||
|
|
document.getElementById("proof").innerHTML = JSON.stringify(p, null, 1);
|
||
|
|
});
|
||
|
|
}
|
||
|
|
|
||
|
|
</script>
|
||
|
|
<body onLoad="onLoad()">
|
||
|
|
<h1>iden3</h1>
|
||
|
|
<h2>Zero knowledge proof generator</h2>
|
||
|
|
<button onClick="calcProof()">Test</button>
|
||
|
|
<div id="time"></div>
|
||
|
|
<pre id="proof"></pre>
|
||
|
|
|
||
|
|
</body>
|
||
|
|
</html>
|
||
|
|
```
|
||
|
|
|
||
|
|
You can test it by running a web server on the example directory
|
||
|
|
|
||
|
|
```
|
||
|
|
npm -g install http-server
|
||
|
|
cd example
|
||
|
|
http-server .
|
||
|
|
```
|
||
|
|
|
||
|
|
And then navegate to [http://127.0.0.1:8080](http://127.0.0.1:8080)
|
||
|
|
|
||
|
|
The generated proof can be cut and pasted to `example/proof` and tested with snarkjs
|
||
|
|
|
||
|
|
```
|
||
|
|
snarkjs verify
|
||
|
|
``
|
||
|
|
|
||
|
|
## Building wasm.js
|
||
|
|
|
||
|
|
```
|
||
|
|
npm run build
|
||
|
|
```
|
||
|
|
|
||
|
|
## Testing
|
||
|
|
|
||
|
|
```
|
||
|
|
npm test
|
||
|
|
```
|
||
|
|
|
||
|
|
## License
|
||
|
|
|
||
|
|
websnark is part of the iden3 project copyright 2019 0KIMS association and published with GPL-3 license. Please check the COPYING file for more details.
|