[tor-talk] Fingerprinting issue in Tor Browser for macOS

Matthew Finkel matthew.finkel at gmail.com
Mon Apr 30 21:57:45 UTC 2018

On Mon, Apr 30, 2018 at 04:26:00AM +0000, Nathaniel Suchy (Lunorian) wrote:
> When using Tor Browser for macOS, the EFF's tool panoptclick shows that
> a large amount of fonts are available, while Tor Browser for Linux
> claims only Wingdings is available. This could allow a website know
> whether a Tor User is using Linux or not helping to create a unique
> fingerprint. Thoughts?

Yes, sadly this is the current state. The three supported platforms for
Tor Browser are distinguishable by looking at a user's available fonts.
This is current a compromise between fingerprintability and usability.
Please see the Tor Browser Design document for additional details [0].
However, note this isn't the only method for identifying the underlying

Section 4.6, Subsection "Specific Fingerprinting Defenses in the Tor
Browser", Item 6. Fonts

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