npm package: @ov0/elliptic
Description: EC cryptography
Author: Fedor Indutny
Latest version: 6.6.1

# Elliptic [![Build Status](https://secure.travis-ci.org/indutny/elliptic.png)](http://travis-ci.org/indutny/elliptic) [![Coverage Status](https://coveralls.io/repos/indutny/elliptic/badge.svg?branch=master&service=github)](https://coveralls.io/github/indutny/elliptic?branch=master) [![Code Climate](https://codeclimate.com/github/indutny/elliptic/badges/gpa.svg)](https://codeclimate.com/github/indutny/elliptic)

Fast elliptic-curve cryptography in a plain javascript implementation.

NOTE: Forked from [Elliptic](https://www.npmjs.com/package/elliptic) since the original library is not compatible with react-native. Use this fork as a replacement.

## Supported curves

Elliptic.js support following curve types:

* Short Weierstrass
* Montgomery
* Edwards
* Twisted Edwards

Following curve 'presets' are embedded into the library:

* `secp256k1`
* `p192`
* `p224`
* `p256`
* `p384`
* `p521`
* `curve25519`
* `ed25519`
* `secp192k1`  not existed in the original library

NOTE: That `curve25519` could not be used for ECDSA, use `ed25519` instead.

## For react-native users

Please add a crypto library like expo-crypto or react-native-quick-crypto

```sh
yarn add expo-crypto
```
or
```sh
yarn add react-native-quick-crypto
```

Using babel-plugin-module-resolver

```sh
yarn add --dev babel-plugin-module-resolver
```

Then edit your babel.config.js

```js
module.exports = {
  presets: ['module:metro-react-native-babel-preset'],
  plugins: [
+   [
+     'module-resolver',
+     {
+       alias: {
+         'crypto': 'react-native-quick-crypto',
+         'stream': 'readable-stream',
+         'buffer': '@craftzdog/react-native-buffer',
+       },
+     },
+   ],
    ...
  ],
};
```

### Implementation details

ECDSA is using deterministic `k` value generation as per [RFC6979][0]. Most of
the curve operations are performed on non-affine coordinates (either projective
or extended), various windowing techniques are used for different cases.

All operations are performed in reduction context using [bn.js][1], hashing is
provided by [hash.js][2]

### Related projects

* [eccrypto][3]: isomorphic implementation of ECDSA, ECDH and ECIES for both
  browserify and node (uses `elliptic` for browser and [secp256k1-node][4] for
  node)

#### LICENSE

This software is licensed under the MIT License.

Copyright Fedor Indutny, 2014.

Permission is hereby granted, free of charge, to any person obtaining a
copy of this software and associated documentation files (the
"Software"), to deal in the Software without restriction, including
without limitation the rights to use, copy, modify, merge, publish,
distribute, sublicense, and/or sell copies of the Software, and to permit
persons to whom the Software is furnished to do so, subject to the
following conditions:

The above copyright notice and this permission notice shall be included
in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN
NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
USE OR OTHER DEALINGS IN THE SOFTWARE.

[0]: http://tools.ietf.org/html/rfc6979
[1]: https://github.com/indutny/bn.js
[2]: https://github.com/indutny/hash.js
[3]: https://github.com/bitchan/eccrypto
[4]: https://github.com/wanderer/secp256k1-node