Interoperable Private Attribution

[martinthomson]

Request for Mozilla Position

• Specification Title: Interoperable Private Attribution (IPA)
• Specification or proposal URL (if available):
• Explainer URL (if available): https://github.com/patcg-individual-drafts/ipa/blob/main/IPA-End-to-End.md
• Mozillians who can provide input: @martinthomson (that's me, ヾ(⌐■_■)ノ)

Other information

IPA proposes a system that enables cross-site attribution. The idea is to provide businesses that use advertising with a way to measure how their advertising is performing without having to rely on tracking. To do this, IPA assigns users with an identifier - a match key - that cannot be used outside of a multi-party compute (MPC) system. The MPC system only executes a specific protocol that has been vetted to ensure that it only provides aggregated information.

This is a system that I've been working on for some time, so I might be biased. I'll ask someone else to post a conclusion or at least ensure that there is independent sign off.

[martinthomson]

OK, having filed this and then sat on it for a long time, it's a bit awkward closing this in this way.

Overall, Mozilla is positive on this general idea. This is a privacy-first approach to solving a problem that is important for advertisers. A solution here would be a big deal, both for the advertising industry and for privacy.

However, a lot has changed since this issue was opened. Though we really thought things were looking good at the time the issue was opened, IPA looks very different now. Worse, there is still a lot of uncertainty about the final shape it might take. We're making a lot of progress with help now from both Apple and Google, but this proposal still doesn't really meet Mozilla's standards for taking a position.

Position: defer is therefore the only reasonable conclusion we can take at this stage. We'll open another issue when things are more fully baked.