Supercookie

lastmod 2021-02-10created 2021-02-102 edits

Supercookie uses favicons to assign a unique identifier to website visitors.

Unlike traditional tracking methods, this ID can be stored almost persistently and cannot be easily cleared by the user.

Features

• Uses favicons to assign a unique ID to each web visitor
• Stored almost permanently and cannot be easily deleted by the user
• Works even in incognito mode; not removed by clearing the cache

Note: this repo was made for demo/educational purposes

How it works

• Favicons are stored in a separate cache called the F-Cache
  • The F-Cache is a cache that stores visited URL information
• When visiting a website, the browser checks whether the favicon is in the F-Cache and, if not, requests it from the server
• This stored/not-stored state is used to generate the client's ID
• Applicable to almost all desktop browsers (Chrome, FF, Safari, Edge) and mobile browsers

See also

• favicon
• web
• cookie

Favorite site

• Github - supercookie