- From: Jason A. Novak <jnovak@apple.com>
- Date: Tue, 24 Apr 2018 10:34:44 -0500
- To: "Patrick H. Lauke" <redux@splintered.co.uk>, public-pointer-events@w3.org
- Cc: public-privacy@w3.org
Hi Patrick - Thanks for the email, apologies for the delayed response. I have a few observations based on my understanding of the specification. Please let me know if I’m misinterpreting the spec. - pointerId appears to be a unique value for the pointer causing the event. I did not see anything regarding how frequently pointerIds should be reset, and as a result it seems like this could be a long term fingerprinting mechanism. It would be a good mitigation to specify that user agents should reset these pointerIds on with some frequency and that the values not be predictable (e.g. generated randomly with cryptographically strong randomness). - There’s a good discussion of the fact that the data exposed in pointer events — the angle or tilt at which a pen input is held, the geometry of the contact surface, and the pressure exerted on the stylus or touch screen — could be used to fingerprint a user but there’s no mention made of mitigations. It would be a good mitigations to specify that user agents could either not provide precise values by default but rather could round the values provided; or user agents could add some element of jitter to their responses. - Based on my read of the specification, I think that the pointer information plus timing of events could be used by a malicious website to determine if a user was using assistive technologies. This may be a consideration to call out in the Security & Privacy considerations, perhaps in a more general way, e.g. “the use of certain input technologies may reveal sensitive information about the user themselves” Best, Jason > On Apr 4, 2018, at 2:34 PM, Patrick H. Lauke <redux@splintered.co.uk> wrote: > > (Expanding the automated call for wide review sent here: https://lists.w3.org/Archives/Public/public-review-announce/2018Apr/0000.html) > > Hello, > > The Pointer Events Working Group requests review of the following specification before 2018-04-25: > > Pointer Events Level 2 > https://www.w3.org/TR/2018/WD-pointerevents2-20180404/ > > The group requests feedback via public-pointer-events@w3.org > > This publication is a Pre-Candidate Recommendation Draft under the > 2014 Process [1]. Therefore, the group is looking for confirmation > that it has satisfied its relevant technical requirements and > dependencies with other groups. > > The group has specifically asked for feedback on the following: > > ============================================ > See the revision history from Pointer Events Level 1 https://www.w3.org/TR/2018/WD-pointerevents2-20180404/#revision-history. This specification primarily clarifies aspects of the previous specification which were vague and led to interoperability issues. > > The specification also now features a "Security and privacy considerations" section https://www.w3.org/TR/2018/WD-pointerevents2-20180404/#security-and-privacy-considerations (which was not a requirement at the time Level 1 was published). > > Note that there remains one open item which has not been covered in this version https://github.com/w3c/pointerevents/issues/173. However, the groups feels that this item, once resolved, won't result in a major substantive change (only a single additional clarifying paragraph), and would therefore welcome feedback on the specification in its current state. > ============================================ > > [1] https://www.w3.org/wiki/DocumentReview > > P > -- > Patrick H. Lauke > > www.splintered.co.uk | https://github.com/patrickhlauke > http://flickr.com/photos/redux/ | http://redux.deviantart.com > twitter: @patrick_h_lauke | skype: patrick_h_lauke >
Received on Tuesday, 24 April 2018 15:35:42 UTC