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bigint-crypto-utils

Utils for working with cryptography using native JS (ES-2020) implementation of BigInt. It includes some extra functions to work with modular arithmetic along with secure random numbers and a fast strong probable prime generator/tester (parallelized multi-threaded Miller-Rabin primality tests if workers are supported). It can be used by any Web Browser or webview supporting BigInt and with Node.js (>=10.4.0).

The operations supported on BigInts are not constant time. BigInt can be therefore unsuitable for use in cryptography. Many platforms provide native support for cryptography, such as Web Cryptography API or Node.js Crypto.

Installation

bigint-crypto-utils is distributed for web browsers and/or webviews supporting BigInt as an ES6 module or an IIFE file; and for Node.js (>=10.4.0), as a CJS module.

bigint-crypto-utils can be imported to your project with npm:

npm install bigint-crypto-utils

NPM installation defaults to the ES6 module for browsers and the CJS one for Node.js.

For web browsers, you can also directly download the IIFE bundle or the ES6 bundle module from GitHub.

Usage examples

Import your module as :

Node.js

const bigintCryptoUtils = require('bigint-crypto-utils')
... // your code here

JavaScript native or TypeScript project
```
import * as bigintCryptoUtils from 'bigint-crypto-utils'
... // your code here
```
BigInt is ES-2020. In order to use it with TypeScript you should set lib (and probably also target and module) to esnext in tsconfig.json.

JavaScript native browser ES6 mod

<script type="module">
   import * as bigintCryptoUtils from 'lib/index.browser.bundle.mod.js'  // Use you actual path to the broser mod bundle
   ... // your code here
 </script>

JavaScript native browser IIFE

<head>
  ...
  <script src="../../lib/index.browser.bundle.js"></script> <!-- Use you actual path to the browser bundle -->
</head>
<body>
  ...
  <script>
    ... // your code here
  </script>
</body>

An example of usage could be:

/* A BigInt with value 666 can be declared calling the bigint constructor as 
BigInt('666') or with the shorter 666n.
Notice that you can also pass a number to the constructor, e.g. BigInt(666). 
However, it is not recommended since values over 2**53 - 1 won't be safe but 
no warning will be raised.
*/
const a = BigInt('5')
const b = BigInt('2')
const n = 19n

console.log(bigintCryptoUtils.modPow(a, b, n)) // prints 6

console.log(bigintCryptoUtils.modInv(2n, 5n)) // prints 3

console.log(bigintCryptoUtils.modInv(BigInt('3'), BigInt('5'))) // prints 2

console.log(bigintCryptoUtils.randBetween(2n ** 256n)) // Prints a cryptographically secure random number between 1 and 2**256 bits.

async function primeTesting () {
  // Output of a probable prime of 2048 bits
  console.log(await bigintCryptoUtils.prime(2048))

  // Testing if a number is a probable prime (Miller-Rabin)
  const number = 27n
  const isPrime = await bigintCryptoUtils.isProbablyPrime(number)
  if (isPrime) {
    console.log(`${number} is prime`)
  } else {
    console.log(`${number} is composite`)
  }
}

primeTesting()

You can find examples in the examples folder of the repository.

4.2 KiB Raw Blame History

bigint-crypto-utils

Installation

Usage examples

API reference documentation

4.2 KiB

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