Random Numbers

A library which allows the selection of a random number between a group of people that do not trust each other. Uses the following algorithm (where n is the highest number to select, 0 is always the lowest):

1. All users select a random number between 0 and 2 ^ ceil(log2(n)). The results are hashed with a nonce using a secure hashing algorithm and shared with the group:

| User | Generated Number | Nonce | Hash | |-------|------------------|-------|--------------| | Alice | 2 | 5h4wh | 5663653j356j | | Bob | 7 | w45hh | 56j35j35j535 | | Eve | 5 | wzghk | zdfg34t4353y |

2. Once a user receives the hash of every other participant, they reveal their randomly generated number and their nonce.

3. All generated numbers are then xor'd together and normalised to

Usage:

const { RandInt } = require('@femto-host/randomNumber')

// pick a random integer from 1 to 20 (inclusive)
const generator = new RandInt(1, 20)

const myPart = generator.gen()

/* implement some part sharing method

1. share `myPart.hash` with others
2. share `myPart` with others after everyone has shown you their hash
*/

generator.finalise(parts)