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    The Spanner
    Web security blog

    Made by Gareth Heyes
    Follow me on Twitter: @garethheyes

    Javascript for hackers!

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    Tracking without cookies

    By Gareth Heyes (@hackvertor)

    Published 18 years 10 months ago • Last updated March 22, 2025 • ⏱️ < 1 min read

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    I've created a simple script after discussions on a mailing list I'm a member of. The idea was to create a unique identifier without using a full IP address or cookies. It works using javascript to gather information about the browser (screen depth, user agent etc), it then takes all this information and creates a unique hash and returns the length of the hash to create the identifier (between 10-32 characters).

    The script assumes the target user would only use one browser and have javascript enabled, I'm not sure if it could be used for production code but I thought it was worth looking into and any feedback would be helpful.

    Probe POC

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