A digital fingerprint is a string that represents a unique id of a device (browser).
The more unique is the browser, the more it has a one on one relationship with a user.
A digital fingerprint may be computed for a device:
The below example is a device characteristic fingerprinting that has been computed with the valve library.
A characteristic device fingerprinting is computed by collecting characteristics of a user's device and by generating a unique string of this collection via a hash function.
Example of characteristics:
See example
Canvas fingerprinting is a type of browser or device fingerprinting technique that was first presented by (2012) Mowery and Shacham in 2012 (Pixel Perfect: Fingerprinting Canvas in HTML5) -
The rendering of a canvas is heavily dependent on the device.
Algo: Render a picture on the canvas > To Base64 encoded > digest function to get the fingerprint value.
An etag is an unique identifier resource send with a HTTP request.
Because the etag is used by the browser when validating the cache in a conditional request, it could be used as fingerprint.
Valve is a browser fingerprinting library (Valve/fingerprintjs2) that implements a characteristics fingerprinting. The example is based on it.
https://www.npmjs.com/package/@ch1/browser-dna
See also:
Panopticlick, Eckersley’s “open-source” implementation of browser fingerprinting. They take: