Few Realize “Private Mode” Is Not Really PrivatePreliminary results of a user study
This ongoing research is being conducted by Ruba Abu-Salma, a Ph.D student in Computer Science from University College London (UCL), and Brave’s Chief Scientist, Dr. Ben Livshits. The final findings will be submitted as a paper in the next several weeks.
Private browsing is a privacy-enhancing tool, where the web browser does not record users’ private browsing activities on the local device . It is a special mode that allows users to browse the Internet without saving any information (e.g., cookies, temporary files) about the websites they have visited in private mode.
Prior work has quantitatively (through survey studies) investigated whether users are aware of private browsing, what they use it for, and whether they understand what it does [2, 3, 4, 5, 6]. Most surveyed respondents were either unaware of private browsing, or did not use it. Further, the vast majority of respondents had misconceptions about private browsing — such as incorrectly believing private browsing protects against visited websites, ISPs, and governments. However, prior work has not investigated why users misunderstand the benefits and limitations of private browsing.
In this work, we seek to explore why users misunderstand private browsing by investigating their mental models of private browsing and its security goals. We also study users’ private browsing habits. We do so by conducting a qualitative, interview-based study with users and non-users of private browsing. The value of conducting qualitative research lies in providing a holistic understanding of the phenomenon under enquiry using predominantly subjective qualitative data, which can be later supplemented by quantitative data.
Our Study: Exploring User Mental Models of Private Browsing
We hypothesize that users’ mental models of private browsing are diverse and do not necessarily map to the narrow set of threats against which browsers actually protect. In our study, we build on prior work and conduct a qualitative study to explore users’ mental models of private browsing and its security goals. We also study how people use private browsing.
Typically, a study of this nature [a qualitative user study] involves between 12 and 25 participants [7, 8]. To recruit our 25 participants, we posted flyers and distributed leaflets in London, UK. We asked interested participants to complete an online screening questionnaire. We aimed to recruit a demographically-diverse sample of participants — in terms of gender, age, race, educational level, and employment status — to assess whether participants’ demographics affected the robustness of their mental models. We also assessed participants’ technical background. Further, we provided participants with a list of different web browsers, and then asked which browsers they used. Google Chrome was the most used web browser by our participants, followed by Firefox, Safari, Internet Explorer, and Brave, respectively.
We now present some preliminary findings of our qualitative study. We do not report how many participants mentioned each finding in this post because this is ongoing work. We only describe high-level findings and insights.
What are users’ mental models of private browsing?
Participants drew their mental models of private browsing. We show some of the participant drawings throughout the post, to illustrate participants’ conceptual understanding of the term “private browsing.”
Although all participants mentioned that they had heard of the term “private browsing,” and felt confident explaining it, almost all participants associated private browsing with privacy tools that provide more protection than what private browsing in Google Chrome, Firefox, Internet Explorer, and Microsoft Edge guarantees. For example, some participants associated private browsing with secure browser connections (i.e., network encryption). Others associated private browsing with end-to-end encrypted communications, anonymous communications (using a VPN or Tor), or user authentication. The drawings below explain some of our participants’ mental models of private browsing.
Who uses private browsing?
We also investigated users’ private browsing habits. There appear to be three types of users:
- Habitual users: those who regularly browse in private mode and describe themselves as “paranoid” or “cautious.” Participants who used private mode for all browsing activities reported using private browsing made them feel “safer.”
- Ephemeral users: those who occasionally browse in private mode depending on their browsing activities and the websites they visit.
- Former users: those who have used private mode, but stopped using it mainly due to (1) lack of utility; (2) lack of usability; (3) misperceptions of private browsing.
We found participants who had browsed in private mode did not necessarily visit “embarrassing websites.” Many participants used private browsing for logging into a service using another account, online shopping, or developing/debugging software.
Alarmingly, some participants performed several browsing activities that they regarded as sensitive in private mode while being authenticated to their personal online accounts (e.g., their Google or YouTube account), believing their search history would be deleted after exiting private browsing.
Participants who stopped browsing in private mode did so due to:
- Lack of utility – e.g., some participants stopped using private browsing because they thought browsers did not allow extensions to run in private mode (although users can manually enable extensions in private mode in most browsers);
- Lack of usability – e.g., some participants reported all entries added to the browser history file while privately browsing would get deleted after they exited private mode;
- Misperceptions of private browsing – e.g., some participants perceived those who browse in private mode as, for example, people who are up to no good.
Finally, participants who occasionally browsed in private mode (ephemeral users) or stopped browsing in private mode (former users) perceived the routine/daily use of private browsing as paranoid. In particular, they described habitual users of private mode as “paranoid people,” “people who have something to hide,” or “people who are up to no good.”
What do users want from private browsing?
Most participants expected that anyone who has physical access to their device should find no evidence of the websites they visited in private mode. Further, the vast majority of non-technical, “unsophisticated” participants expected a private mode that works properly not to link the user’s activities in private mode to those in public mode, as well as not to track the user’s activities on other websites. Additionally, most participants expected a website visited in private mode not to determine whether the user’s web browser is currently in private mode. Participants did not consider how IP addresses and various browser features – such as screen resolution and timezone – can be used by a visited website in private mode to fingerprint users.
Some browsers have added privacy functions to help reduce website tracking. For example, Brave has recently added onion routing (Tor) as an option to its private tabs. Also, Firefox disables third-party cookies while browsing in private mode. However, no web browser currently meets all users’ expectations.
Conclusions: Designing Better Browser Disclosures
Our preliminary findings suggest that users’ mental models of private browsing are diverse and do not necessarily map to the definition generally agreed upon by the security and privacy community or browser vendors. Prior work has shown that users usually overestimate the benefits of private browsing [2, 3, 4]. We argue:
- Users’ understanding of the security goals of private mode depends on their interpretation of the term “private browsing.”
- A key user-related challenge for private browsing is not adoption (i.e., trying to increase the adoption of private browsing by mainstream users, as prior work (e.g., [2, 3, 4]) has been investigating), but appropriate use. We need to ensure that people have correct mental models of private browsing and understand what it does before adopting this privacy tool. This could be achieved through the design of effective browser disclosures – a browser disclosure is the full-page explanation a browser presents when users open a new window or tab in private mode.
The high-level description of private mode as a “private window” or a “private tab” is vague, and insufficiently informs users (especially first-time users who have not used private browsing before) of the security goals of private mode. As our findings, as well as prior work [5, 6], suggest, current browser disclosures are not effective in communicating the benefits and limitations of private mode. Little work has investigated how to design effective browser disclosures. We, therefore, plan to perform a participatory design study with end users to develop better browser disclosures, through the use of illustrations and diagrams, to better communicate the security goals of private browsing and address users’ misconceptions.
- Gaurav Aggrawal, Elie Bursztein, Collin Jackson, and Dan Boneh. An Analysis of Private Browsing Modes in Modern Browsers. In Proc. USENIX Security Symposium, 2010.
- Xianyi Gao, Yulong Yang, Huiqing Fu, Janne Lindqvist, and Yang Wang. Private Browsing: An Inquiry on Usability and Privacy Protection. In Proc. Workshop on Privacy in the Electronic Society, 2014.
- DuckDuckGo. A Study on Private Browsing: Consumer Usage, Knowledge, and Thoughts. Technical Report, January, 2017.
- Elie Bursztein. Understanding How People Use Private Browsing. Technical Report, July, 2017.
- Yuxi Wu, Panya Gupta, Miranda Wei, Yasemin Acar, Sascha Fahl, and Blase Ur. Your Secrets Are Safe: How Browsers’ Explanations Impact Misconceptions About Private Browsing Mode. In Proc. Conference on World Wide Web, 2018.
- Hana Habib, Jessica Colnago, Vidya Gopalakrishnan, Sarah Pearman, Jeremy Thomas, Alessandro Acquisti, Nicolas Christin, and Lorrie Faith Cranor. Away From Prying Eyes: Analyzing Usage and Understanding of Private Browsing. In Proc. Symposium on Usable Privacy and Security, 2018.
- Tamy Guberek, Allison McDonald, Sylvia Simioni, Abraham H Mhaidli, Kentaro Toyama, and Florian Schaub. Keeping a Low Profile?: Technology, Risk and Privacy among Undocumented Immigrants. In Proc. ACM Conference on Human Factors in Computing Systems, 2018.
- Rock Stevens, Daniel Votipka, Elissa M. Redmiles, Colin Ahern, Patrick Sweeney, and Michelle L. Mazurek. The Battle for New York: A Case Study of Applied Digital Threat Modelling at the Enterprise Level. In Proc. USENIX Security Symposium, 2018.
Continue reading for news on ad blocking, features, performance, privacy and Basic Attention Token related announcements.
New online advertising model upends current systemwith 70% revenue share to users and privacy by designToday we’re previewing our new digital advertising model in Brave’s Developer channel. Developers and testers using the latest desktop browser build for macOS and...
2018 highlights include 5X MAU growth, major product redesigns, and key partnershipsAs we look ahead to 2019 and our upcoming Brave 1.0 release with Brave Ads that will reward users for their attention with Basic Attention Tokens (BAT), we wanted to share some of our...
Brave Rewards is our anonymous donation system integrated directly into the Brave desktop browser. It is accessible to users from the URL bar via the BAT (Basic Attention Token) logo, and though off by default, can be easily switched on with the slider. Publishers and...
Brave San Francisco
512 Second St., Floor 2
San Francisco, CA 94107
9 Appold St
London, EC2A 2AP
- $1 Million Token Giveaway
- 404 Page
- About Ad Replacement
- About Brave
- Ads User Trials
- Assets for Creators
- Be Brave and support me!
- Be Brave and support me!
- Become a Brave Rewards Creator
- Best Adblock for YouTube
- BitTorrent – Browse with integrity
- BitTorrent – Secure & Fast Browsing
- Block Ads and Trackers with Brave!
- Brave Branding Assets
- Brave Linkbubbles for Social Media & Pocket
- Brave Research
- Brave Rewards Creator
- Brave Signing Key
- Coindesk Partnership for faster, ad-free browsing
- Creator Referral Program
- Download Brave Ads Trials
- Download Brave Beta
- Download Brave Dev
- Download Browser with Adblocker for Mobile & Desktop
- Dr Johnny Ryan FRHistS
- Experience the Fastest & Safest Web Browser
- Experience the Fastest & Safest Web Browser
- Free 2-year subscription to Barron’s
- Free 2-year subscription to MarketWatch
- Frequently Asked Questions
- Join us to Change the Web Together
- Media Assets
- News on Privacy, Adblock and Browsers
- Secure, Fast & Private Web Browser with Adblocker
- See Current Stats
- Thanks for Downloading Brave
- The Brave Community
- Townsquare Media – PopCrush
- Townsquare Media – Taste Of Country
- Townsquare Media – Ultimate Classic Rock
- Townsquare Media – XXL
- Youth Involvement in Open Source Technologies
Posts by category
- Category: AMA
- Category: Announcements
- Brave Previews Opt-in Ads in Desktop Browser Developer Channel
- Brave passes 5.5 million monthly active users and features over 28,000 Verified Publishers
- Brave Rewards Update
- New BAT Tipping Banner for Brave Creators, Available with Today’s Desktop Browser Update
- Brave Software Joins AdLedger
- New Brave version now available for download for iPhones and iPads, with significant performance gains
- Brave Upgrades Users of its Desktop Browser to its Redesigned, Faster Version
- “Best of the Brave” Video Contest Winners Are Rewarded with 115K BAT
- SpeedReader: Fast and Private Reader Mode for the Web
- Brave Sponsors Cal Hacks 5.0, the World’s Largest Collegiate Hackathon
- New Brave Browser Release Available for General Download on Brave.com
- The New Brave is 22% Faster
- Beta Release of Redesigned Brave Desktop Browser is Available Today for Download and Testing
- Brave Launches 100K BAT “Best of the Brave” Video Contest for Online Creators and Publishers
- Civic to Offer Secure Identity Verification Services on the Brave Publisher Platform
- Fast and Private Brave Browser Chooses Qwant as its Default Search Engine in France and Germany
- Regulatory complaint concerning massive, web-wide data breach by Google and other “ad tech” companies under Europe’s GDPR
- Few Realize “Private Mode” Is Not Really Private
- Understanding Redirection-Based Tracking
- Brave Browser iOS App Now Offers DuckDuckGo Search in Private Tabs
- Brave Passes 3 Million Monthly Active Users and Makes Top 10 List in the Play Store in 21 Countries
- Brave Introduces Beta of Private Tabs with Tor for Enhanced Privacy while Browsing
- Brave Welcomes Dr. Johnny Ryan to its Leadership Team as Chief Policy and Industry Relations Officer
- Brave Launches User Trials for Opt-In Ads That Reward Viewers
- Brave Users Get Rewarded to Browse
- Brave Proposes a Machine Learning Approach for Ad Blocking
- New Brave Version Features Tab Improvements for Enhanced Performance
- Global Brave News — Brave Officially Opens London Office and Presents in Singapore and Korea
- Brave and Townsquare Partner to Monetize Ad-blocking Traffic and Test Blockchain-based Digital Advertising
- Brave Update: Partners, Creators, Users, and Growth – April 2018
- Dow Jones Media Group Partners With Brave Software To Offer Premium Content To Users and Test Blockchain-Based Payment Technology
- Brave Distributes Million Dollar Referral Program to Content Creators
- Brave Unveils Development Plans for Upcoming 1.0 Browser Release, Including Transition to Chromium Front-End
- Million Dollar BAT Giveaway to Brave Users Now Paid Out to Rewarded Content Creators
- Twitch Support
- Let’s Encrypt Sponsorship
- Brave Launches Million Dollar Referral Program Supporting Publishers And YouTube Creators With Crypto-Tokens
- Multi-property Support Now Live for Brave-verified Creators
- New Brave Release Available For Desktop Users With Across-the-board Improvements And Updates
- Brave-verified Publishers Double in One Week with Ongoing $1 Million Crypto-token Giveaway
- Brave Announces $1 Million Crypto-Token Giveaway
- Update: Brave Browser and BAT Achievements in 2017 and Goals for 2018
- An Inside Look at Brave Development
- Brave and DuckDuckGo Partner to Improve Privacy on the Web
- Brave Grants 300,000 Promotional Tokens to Browser Users
- Funding your Brave Wallet
- Brave expands Basic Attention Token platform to YouTube
- Tips and Tricks for Brave on Your Phone
- ETHWaterloo Hackathon: Integrating MetaMask into Brave
- BAT Mercury Launch
- Brave expands its leadership team with Ben Livshits as Chief Scientist and David Temkin as Chief Product Officer
- Unpublishing Link Bubble
- Loading Chrome Extensions in Brave
- Introducing Brave Payments
- Brave’s Response to the NAA: A Better Deal for Publishers
- Category: Brave Insights
- Brave requests European Commission antitrust examination of online ad market
- 38 businesses and organizations urge European Governments to break ePrivacy deadlock
- French regulator shows deep flaws in IAB’s consent framework and RTB
- Brave calls for a “United States GDPR” in letter to the National Telecommunications and Information Administration
- Why GDPR is Kryptonite to Google & Facebook on Anti-Trust
- Brendan Eich writes to the US Senate: we need a GDPR for the United States
- Critical data protection problems in the IAB’s new OpenRTB 3.0 Spec
- Brave Writes to All 28 EU Member States, Defending ePrivacy Regulation’s “Privacy By Design and By Default”
- Europe’s top court signals new risk for marketers from ad tech
- Category: Community
- Category: GDPR
- Category: New Features
- Category: Policy
- Category: Press
- Brave ad-blocking browser gets Chrome’s extensions with major new version
- Crypto-Funded Brave Browser Hits 10 Million Downloads in Google Play Store
- Le navigateur Brave dépasse les 10 millions de téléchargements
- Brave advances browser privacy with Tor-powered tabs
- Blockchain browser Brave starts opt-in testing of on-device ad targeting
- What’s an Online Ad Worth? Blockchain Might Help With That
- Crypto-powered Brave Browser Hits 5 Million Downloads in Google Play Store
- Ad-blocking Brave browser to give crypto-payment tokens to everyone
- Ad-blocking browser Brave signs up Dow Jones Media Group as a partner
- Category: Research
- Category: Rewards
- Category: Security & Privacy