Privacy Preserving Attribution

[sertonix]

When PPA is disabled the functions are a no-op. This skips the argument checking too so it is possible to detect whenever or not PPA is enabled. From what I have seen it should be possible to hide whenever PPA is enabled or disabled.

let enabled = false;
try {
  // The ~ is considered an invalid url and will cause an error when PPA is enabled.
  navigator.privateAttribution.saveImpression({ type: "view", index: 6, ad: "shoes", target: "~" });
} catch (e) {
  if (e instanceof DOMException)
    enabled = true;
}

Since PPA is an Origin Trial you currently need to set dom.origin-trials.private-attribution.state: 1 for the API to be available on any website.

[Thorin-Oakenpants]

AFAICT ... when this becomes available on any website ... this is not a thing

• see https://github.com/mozilla/explainers/issues/11#issuecomment-2228913120

• The API appears to function fully when someone is opted out, but no private information is released. That is, saveImpression appears to save something (but saves nothing), and measureConversion generates a measurement message that contains all zero values. From the perspective of the sites involved, things appear to be exactly the same as someone who has the feature enabled.

[sertonix]

Then this is a bug in firefox. Made a report here https://bugzilla.mozilla.org/show_bug.cgi?id=1908470

[Thorin-Oakenpants]

sorry, I have a lot going on and am not really following this

[Thorin-Oakenpants]

I honestly can't quite follow this - I tried the other day in nightly with it enabled and not enabled and couldn't detect a difference (using console on live web sites)

edit: OK I needed to flip the pref for all sites? right?

[sertonix]

Setting dom.origin-trials.private-attribution.state to 1 enables the API for all sites. This is needed cause the API is experimental (and the other options are too complicated).

[Thorin-Oakenpants]

okie dokie - soz, am super busy with TB stuff - ESR128 is a huge jump :)

[Thorin-Oakenpants]

ok, so being a Origin Trial (OT) this currently doesn't make a viable FP as it's not universal. And once 1908470 is fixed then when OT becomes obsolete (i.e enabled universally?) it's no longer a FP vector. So closing. But good catch