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Microsoft claims Google bypassed its browser privacy too

P3P policy flaw gave automatic access

By Iain Thomson, 20 Feb 2012

Updated Microsoft has released data showing that Google has been bypassing the user-defined privacy settings in Internet Explorer by using incorrect P3P identification terms.

“When the IE team heard that Google had bypassed user privacy settings on Safari, we asked ourselves a simple question: is Google circumventing the privacy preferences of Internet Explorer users too?” Dean Hachamovitch, VP of Internet Explorer wrote in a blog post. “We’ve discovered the answer is yes: Google is employing similar methods to get around the default privacy protections in IE and track IE users with cookies.”

Redmond had been rather pleased about the fact that it hadn’t suffered the same kind of problems as Apple against Google’s quest for information on users. But now it claims Google has got to its users, too, by circumventing protections guaranteed by the Platform for Privacy Preferences (P3P) system its browser supports.

The P3P system uses three or four character code chunks to describe the privacy policy of the requester. As an example, Hachamovitch used “TAI,” which indicates “Information may be used to tailor or modify content or design of the site where the information is used only for a single visit to the site and not used for any kind of future customization.”

However, if the code is not recognized, Internet Explorer will accept it anyway and allow the requester full access to the user for third-party cookie purposes. Google didn’t do this “in a manner consistent with the technology,” Microsoft suggests, as it used the following message:

“P3P: CP="This is not a P3P policy! See http://www.google.com/support/accounts/bin/answer.py?hl=en&answer=151657 for more info."

Microsoft described being able to bypass its browser’s privacy settings in this way as “a nuance in the P3P specification,” but as was pointed out by El Reg last year and in academic papers in 2010, it’s a tactic that’s been widely used to circumvent the privacy wishes of the browser user. Microsoft is one of a dwindling band of companies still using P3P, and this latest admission will increase the decay in support.

The news will also come as a fillip to last week’s bipartisan calls for investigations into how Google is bypassing privacy protections on Safari. There’s no word from Google as yet on this, but you can bet it’s not a pretty President’s Day at the Chocolate Factory. ®

Update

"Microsoft uses a “self-declaration” protocol (known as “P3P”) dating from 2002 under which Microsoft asks websites to represent their privacy practices in machine-readable form," Rachel Whetstone, VP of communications and policy at Google, told El Reg in an emailed statement.

"It is well known - including by Microsoft - that it is impractical to comply with Microsoft’s request while providing modern web functionality. We have been open about our approach, as have many other websites."