bigint-mod-arith/src/doc/readme-template.md

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{{PKG_NAME}}

Some extra functions to work with modular arithmetic using native JS (ES-2020) implementation of BigInt. 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

{{PKG_NAME}} 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.

{{PKG_NAME}} can be imported to your project with npm:

npm install {{PKG_NAME}}

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 {{ESM_BUNDLE}} from the repository.

Usage example

Import your module as :

• Node.js

  const {{PKG_CAMELCASE}} = require('{{PKG_NAME}}')
  ... // your code here
  

• JavaScript native or TypeScript project (including Angular and React)

  import * as {{PKG_CAMELCASE}} from '{{PKG_NAME}}'
  ... // 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 {{PKG_CAMELCASE}} from 'lib/index.browser.bundle.mod.js'  // Use you actual path to the broser mod bundle
     ... // your code here
   </script>
  

• JavaScript native browser IIFE

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

And you could use it like in the following:

/* Stage 3 BigInts with value 666 can be declared as BigInt('666')
or the shorter syntax 666n.
Notice that you can also pass a number, e.g. BigInt(666), but 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(bigintModArith.modPow(a, b, n)) // prints 6

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

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

API reference documentation

{{>main}}