random-bigint

Because the generation of random numbers is too important to be left to chance.

purpose

This module generates cryptographically strong pseudo-random BigInts.

usage

const random = require('random-bigint')

// synchronous api, generates a random number between 0 and 2**128-1
const num = random(128) // 128 bits
console.log(typeof num) // 'bigint'
console.log(num) // e.g. 248612378658540041399850947464384774729n

// asynchronous api
random(128, function(err, num) {
	if (err)
		throw err

	console.log(num) // e.g. 248612378658540041399850947464384774729n
})

api

This module exports a single function that is documented below.

random(bits[, cb])

• bits {number} Number of bits.
• cb {Function} Optional (err, num) callback.

Generate a random BigInt in the range 0..2**bits-1.

Uses crypto.randomBytes() to generate the raw random bits and hence produces cryptographically strong pseudo-random numbers.

random() operates synchronously when the callback is omitted. Generating large numbers may block the event loop for a long time.

Bias the result to generate random numbers less than zero:

const random = require('random-bigint')

const bits = 7
const bias = 2n ** BigInt(bits)
const num = random(1 + bits) - bias

console.log(num) // bigint in the range -128n..127n

license

ISC, see the LICENSE file in the top-level directory.