Fingerprinting is a technique, outlined in the research by Electronic Frontier Foundation, of anonymously identifying a web browser with accuracy of up to 94%.
Browser is queried its agent string, screen resolution and color depth, installed plugins with supported mime types, timezone offset and other capabilities, such as local storage and session storage. Then these values are passed through a hashing function to produce a fingerprint that gives weak guarantees of uniqueness.
No cookies are stored to identify a browser.
It's worth noting that a mobile share of browsers is much more uniform, so fingerprinting should be used only as a supplementary identifying mechanism there.
Add this to your Gemfile
gem 'fingerprintjs-rails'
and
bundle install
After that you can add the file to sprockets:
//= require fingerprint
var fingerprint = new Fingerprint().get();Using custom hashing function
var hasher = new function(value, seed){ return value.length % seed; }
var fingerprint = new Fingerprint(hasher).get();This code is MIT licenced:
Copyright (c) 2013 Valentin Vasilyev
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