Subject: Data motivating CH? (From PING)

From: Pete Snyder <[email-masked]>
Date: Tue, 12 Feb 2019 15:19:01 -0800

Hi All,

I’m Pete Snyder from PING.  PING is interested in what data has been gathered / exists to motivate moving fingerprintable values into to passively collectable, log-able headers. Given that the spec increases the risk of privacy-loss (there is a subsection of the spec for this purpose), we're interested in what data exists to show that this risk would be counter balanced by benefit to:

1. A significant portion of web users,
2. On a significant portion of web sites

Does any such data exist? Any relevant information would be extremely useful as we continue considering the proposal.

Best,
Pete Snyder

---

From: Yoav Weiss <[email-masked]>
Date: Wed, 13 Feb 2019 15:41:35 +0100

Hey Pete,

On Wed, Feb 13, 2019 at 12:22 AM Pete Snyder <[email-masked]> wrote:

> Hi All,
>
> I’m Pete Snyder from PING.  PING is interested in what data has been
> gathered / exists to motivate moving fingerprintable values into to
> passively collectable, log-able headers.

I'm sorry, but I have to reject your claims regarding "passively
collectable" as well as "log-able".
More details on why can be found on my reply to the issue you opened
<https://github.com/httpwg/http-extensions/issues/767#issuecomment-463154773>
.

> Given that the spec increases the risk of privacy-loss

Again, I have to reject that claim.

> (there is a subsection of the spec for this purpose)

All specifications nowadays have to include a "Security and Privacy
considerations" section. Are you implying that including such a
considerations section somehow proves that a proposal is less secure or
introduces privacy leaks?

> , we're interested in what data exists to show that this risk would be
> counter balanced by benefit to:
>
> Does any such data exist? Any relevant information would be extremely
> useful as we continue considering the proposal.
>

Data specific to the real-world performance benefits of improved content
negotiation that CH provides can be found here
<https://cloudinary.com/blog/client_hints_and_responsive_images_what_changed_in_chrome_67>.
I believe we're still lacking data on the privacy benefits of using the CH
infrastructure to reduce passive fingerprinting, as this proposal is still
at an early phase.