Private browsing: it's not so private

Research by Stanford University to investigate the privacy of the "private browsing" feature of many Web browsers suggests that the tools aren't all that private after all, and that many kinds of information can be leaked by browsers when using the mode. The paper is due to be presented next week at the USENIX security conference.

"InPrivate Browsing" in Internet Explorer, "Incognito mode" in Chrome, and "Private Browsing" in Firefox and Safari all strive to do the same two things: make it impossible for users of the same computer to figure out which sites the browser has been used to visit, and make it impossible for sites to know whether or not a particular user has previously visited them.

To keep browsing private from other users of the same machine, browsers must discard (or avoid creating) any history entries, cached items, cookies, and so on. To prevent sites from being able to track visitors, the browsers must ensure that they don't send any cookies or other identifiable information from non-private sessions when in private mode.

The researchers found that the browsers' protections were imperfect. Browsers did not properly isolate their private sessions from non-private ones, with the result that suitably crafted sites could trace visitors between private and non-private sessions. Sites could also leave persistent indications that they had been visited, allowing visits to be detected by local users.

The big problem: add-ons

The problem got worse when extensions and plugins were considered. All four browsers tested enabled plugins in private mode, and these plugins can themselves store data that allows both kinds of privacy to be defeated.

One example of such a plugin used to be Adobe Flash; Flash has its own cookie system, and it used to be the case that Flash's cookies did not respect the privacy mode of the browser. Cookies set in private mode persisted, and cookies set in public mode were readable from private mode. Fortunately, Flash has since been fixed, but any plugin could contain similar errors.

Internet Explorer and Chrome both disable browser extensions by default in their private mode; Firefox, however, does not, and this provides yet another avenue by which private information can be leaked.

As part of their research, the team also collected information on how often people use private modes. Though Microsoft advertises InPrivate Browsing as a way for people to buy gifts online without any risk that the recipient will find out, the most common use of private browsing was (shockingly) to explore the Internet's seedy underbelly, keeping prurient interests, rather than birthday presents, private. Even this use was relatively rare; only 8 percent of people used private browsing for their online sexual entertainment, with 6 percent using it for gift shopping and general Web browsing.

The use of private browsing also varied wildly between browsers. Internet Explorer users barely bothered—just 2 percent of them use it, even for X-rated sites—whereas some 14 percent of Safari users prefer to keep their dirty/gift-buying habits to themselves.

Source: ars technica

Tags: browsers

Comments
Add comment

Your name:
Sign in with:
or
Your comment:


Enter code:

E-mail (not required)
E-mail will not be disclosed to the third party


Last news

 
Galaxy Note10 really is built around a 6.7-inch display
 
You may still be able to download your content
 
Facebook, Messenger and Instagram are all going away
 
Minimize apps to a floating, always-on-top bubble
 
Japan Display has been providing LCDs for the iPhone XR, the only LCD model in Apple’s 2018 line-up
 
The 2001 operating system has reached its lowest share level
 
The entire TSMC 5nm design infrastructure is available now from TSMC
 
The smartphone uses a Snapdragon 660 processor running Android 9 Pie
The Samsung Galaxy A5 (2017) Review
The evolution of the successful smartphone, now with a waterproof body and USB Type-C
February 7, 2017 / 2
Samsung Galaxy TabPro S - a tablet with the Windows-keyboard
The first Windows-tablet with the 12-inch display Super AMOLED
June 7, 2016 /
Keyboards for iOS
Ten iOS keyboards review
July 18, 2015 /
Samsung E1200 Mobile Phone Review
A cheap phone with a good screen
March 8, 2015 / 4
Creative Sound Blaster Z sound card review
Good sound for those who are not satisfied with the onboard solution
September 25, 2014 / 2
Samsung Galaxy Gear: Smartwatch at High Price
The first smartwatch from Samsung - almost a smartphone with a small body
December 19, 2013 /
 
 

News Archive

 
 
SuMoTuWeThFrSa
  12345
6789101112
13141516171819
20212223242526
2728293031  




Poll

Do you use microSD card with your phone?
or leave your own version in comments (15)