How to deal with big numbers in javascript [duplicate]

Answer 1

There's a BigInteger library for JavaScript available here:

• jsbn.js

(Note that I haven't used this myself. Try it and see what you think.)

Answer 2

While looking for an big integer library for an ElGamal crypto implementation I tested several libraries with the following results:

I recommend this one: Tom Wu's jsbn.js (http://www-cs-students.stanford.edu/~tjw/jsbn/)

• Comprehensive set of functions and fast

Leemon Baird's big integer library (http://www.leemon.com/crypto/BigInt.js)

• Comprehensive set of functions and pretty fast
• BUT: Negative number representation is buggy!

bignumber.js (https://github.com/MikeMcl/bignumber.js)

• Pretty complete set of functions
• BUT: Converting really big numbers from strings into BigNumber objects result in INFINITY

Scheme arithmetic library for JavaScript (https://github.com/jtobey/javascript-bignum)

• JS-Implementation of Scheme arithmetic functions
• BUT: No function for y= x^e mod n

I haven't tested this by myself: BigNumber (http://jsfromhell.com/classes/bignumber)

• Functions for high precision claculations
• BUT: It's said to be slow due to internal representation of numbers as strings

Answer 3

There is also Silent Matt's library for Big Integers. It does not handle decimals.

Answer 4

It looks like this has been solved before:

What is the standard solution in Javascript for handling big numbers (BigNum)?

http://jsfromhell.com/classes/bignumber

http://www-cs-students.stanford.edu/~tjw/jsbn/

If you only need integers you can use BigInteger.js.