Details on withdrawal

[brodrigu]

PIGIN is far less complex and solves many more of the use-cases for online advertising than TURTLEDOVE.

Can you provide details on why PIGIN was withdrawn?

[michaelkleber]

Quoting myself from https://github.com/michaelkleber/turtledove#pigin :-) :

Feedback from the W3C Web-Advertising Business Group and Privacy Interest Group and from the browser and privacy research communities highlighted weaknesses in that design. The ability to associate an advertiser's interest group assignment with a person's first-party identity on a publisher's site was considered too high of a privacy leak even with that Explainer's proposed mitigations. Additionally, analysis of real-world userlist memberships indicated that even the proposed "small amount of interest group information" would consume too much of a page's Privacy Budget.

In particular, TURTLEDOVE has two key privacy goals that PIGIN doesn't fulfil:

• Advertisers cannot learn the browsing habits of any specific people, even ones who have joined multiple interest groups.
• Web sites cannot learn the interest groups of any specific people who visit them.