Comment by immibis
9 days ago
What should instead happen is that Chrome should stop sending as much of a fingerprint, so that sites won't be able to fingerprint. That won't happen, since it's against Google's interests.
9 days ago
What should instead happen is that Chrome should stop sending as much of a fingerprint, so that sites won't be able to fingerprint. That won't happen, since it's against Google's interests.
This is a fundamental misunderstanding of how TLS fingerprinting works. The "fingerprint" isn't from chrome sending a "fingerprint: [random uuid]" attribute in every TLS negotiation. It's derived from various properties of the TLS stack, like what ciphers it can accept. You can't make "stop sending as much of a fingerprint", without every browser agreeing on the same TLS stack. It's already minimal as it is, because there's basically no aspect of the TLS stack that users can configure, and chrome bundles its own, so you'd expect every chrome user to have the same TLS fingerprint. It's only really useful to distinguish "fake" chrome users (eg. curl with custom header set, or firefox users with user agent spoofer) from "real" chrome users.
What? Just fix the ciphers to a list of what's known to work + some safety margin. Each user needing some different specific cipher (like a cipher for horses, and one for dogs), is not a thing.
>Just fix the ciphers to a list of what's known to work + some safety margin.
That's already the case. The trouble is that NSS (what firefox uses) doesn't support the same cipher suites as boringssl (what chrome uses?).
Part of the fingerprint is stuff like the ordering of extensions, which Chrome could easily do but AFAIK doesn’t.
(AIUI Google’s Play Store is one of the biggest TLS fingerprinting culprits.)
Chrome has randomized its ClientHello extension order for two years now.[0]
The companies to blame here are solely the ones employing these fingerprinting techniques, and those relying on services of these companies (which is a worryingly large chunk of the web). For example, after the Chrome change, Cloudflare just switched to a fingerprinter that doesn't check the order.[1]
[0]: https://chromestatus.com/feature/5124606246518784
[1]: https://blog.cloudflare.com/ja4-signals/
13 replies →
What's the advantage of randomizing the order, when all chrome users already have the same order? Practically speaking there's a bazillion ways to fingerprint Chrome besides TLS cipher ordering, that it's not worth adding random mitigations like this.