Javascripts Math.random is not very random. This library attempts to use the NodeJS crypto library to generate random numbers more randomly. Additionally, getting a random int inside of a range does not use modulo in order to provide a more evenly distrubuted set of numbers.
For why using modulo to find the int for a range is bad see here(http://mathoverflow.net/questions/35556/skewing-the-distribution-of-random-values-over-a-range).
According to ent the entropy of Node's Math.random is 3.304235. Using this module the entropy is 3.451241. I am not able to determine how much this is but atleast secure_random is better. If anyone has ideas to improve the code or how to test it those would be greatly appreciated.
npm install secure_random
or
git clone git@github.com:my8bird/nodejs-secure-random.git
var random = require('./random');
// Just get random data to use as you wish
random.getRandomInt(function(err, value) {
// This value will be between 0 and MAX_INT where MAX_INT is a 32bit value
console.log("Look ma I got some entropy", value);
}
);
// Get a random int between to values
random.getRandomInt(10, 100, function(err, value) {
// The value will between 10-100
console.log("Look ma I got some entropy", value);
}
);