Javascript implementation of the RAPPOR algorithm, described at https://github.com/google/rappor.
npm install rappor
This is an implementation of the rappor algorithm, which allows one to infer statistics about a population while preserving the privacy of individual users. Before using it, you should understand what you do and do not get from this algorithm, by consulting the paper.
var rappor = require('rappor');
var encoder = new rappor.Encoder('userId');
var output = encoder.encode(input);