<location, date> Privacy Badger Take a Bite Out of Tracking Cooper Quintin [email protected] @cooperq <location, date> Electronic Frontier Foundation ● Non-Profit defending civil liberties in the digital world ● Impact litigation, activism, technology ● Projects like HTTPS Everywhere, Let's Encrypt, Panopticlick and Privacy Badger ● I am a staff technologist at EFF – This means I'm a programmer; I can't answer your legal questions <location, date> What We Are Going to Talk About ● Browser Tracking — It's a Bigger Problem Than You May Think ● Why Online Privacy Matters ● Who Is Tracking Us ● How Are They Doing It ● What Can We Do To Stop It <location, date> Your Browsing Is Being Tracked ● Most Websites Include Third-Party Trackers – These are resources which come from a domain other than the one you intended to visit ● This is big business — A Multi-Billion Dollar Industry <location, date> Who is tracking you online? <location, date> Who is Tracking You Online ● First Parties Like Amazon, Facebook, Google – Tracking and privacy are a bit hard to define here ● Malware and Spyware – You may have installed it on purpose – Stopping this is mostly about user education and security ● Third Parties… <location, date> Some Key Players in the Industry <location, date> Third Party Trackers ● Non-consensual ● Ubiquitous ● Hard to avoid ● Strong financial incentive <location, date> Third Party Tracking is Also Useful For Spies ● “NSA uses Google cookies to pinpoint targets for hacking” - Washington Post ● “How the NSA Piggy-Backs on Third-Party Trackers” - Slate.com ● “SECRET ‘BADASS’ INTELLIGENCE PROGRAM SPIED ON SMARTPHONES” - The Intercept <location, date> But, Privacy Is Dead! <location, date> <location, date> <location, date> <location, date> Why Should You Care About Privacy? ● You May Want to Read Things That Are Controversial or Embarassing For Research or Just General Interest ● Data Which May Be Embarassing When Put Together – A search for health insurance quotes and then looking up a disease on Web MD for example ● Chilling Effects <location, date> Privacy lets us make mistakes, play with ideas, and grow as individuals—it gives us the space to discover who we are. <location, date> How Does Online Tracking Work? <location, date> IP Address <location, date> Cookies <location, date> Super Cookies <location, date> Fingerprinting <location, date> How Can Online Tracking be Stopped? <location, date> Adblockers ● Usually only block ads, not necesarilly trackers by default ● Arms race problem <location, date> Incognito Browsing ● Vulnerable to fingerprinting – And some super cookies ● Tor Browser – Unfortunately not usable as main browser for many people <location, date> Policy Work — Do Not Track ● W3C standard ● Opt in to DNT – advertisers will not track you – Really they only don't tell you they are tracking you ● Classic example of design by committee ● Low level of adoption ● Considered a failure <location, date> A Combination of Tech and Policy <location, date> Privacy Badger ● Browser Plugin ● Open Source ● Focuses on completely blocking trackers ● Tries to solve the arms race problem – Uses an algorithm instead of a blacklist – Can cause false positives and false negatives <location, date> How Does Privacy Badger Work? ● Send a DNT=1 header ● Watch for requests to third party domains ● If a third party domain sets a high entropy cookie, add it to a list of potential trackers ● If the tracker is seen on multiple sites – block it ● Of course, there are false positives <location, date> How Does Privacy Badger Work? ● Entropy in Information Theory – The information contained in a message, usually in units such as bits. – A 2 bit message would have 2 bits of entropy or 1 in 4 ● Low entropy cookie: – lang=es; /*About 8 bits of entropy or 1 in 255 */ ● High entropy cookie: – utmz=32c3e3f09a23 /* About 48 bits of entropy */ – Approximately 1 in 281.5 trillion <location, date> How Does Privacy Badger Work? ● Occasionally a tracker can't be blocked without creating significant problems for the user – Youtube, Google Maps, AWS, Paypal, etc. ● For these we block cookies – HTTP and Javascript – Supercookies in the future <location, date> How Does Privacy Badger Work? ● Users can see and adjust what is blocked, greylisted and allowed ● Can disable privacy badger entirely for certain sites if they wish. ● Can opt back in to third parties for certain uses (e.g. Disqus, Youtube comments) <location, date> But what about third party sites that legitimately do not wish to track users? <location, date> The Policy Side — A New DNT ● EFF is working on a new do not track policy ● States that users sending DNT will not be tracked ● Blocking sites that don't respect DNT creates an incentive to respect DNT <location, date> The Policy Side — A New DNT ● User identifiers will be discarded ● Logs will not be kept longer than necessary ● Data can be kept for debugging or security ● Data can be anonymized and aggregated for analytics ● Sites adopting it get automatically whitelisted by Privacy Badger <location, date> The Policy Side — A New DNT ● Right now we have a discussion draft and preliminary policy – https://www.eff.org/dnt-policy ● We Are In Talks With Some Major Internet Companies to Adopt It ● Other Tracker Blocking Software Companies May Adopt it as Well <location, date> What Still Needs to Happen ● Better tracker detection algorithms ● Detect supercookies and fingerprinting ● Localization / UI ● More DNT adoption from third parties <location, date> How You Can Help ● Use Privacy Badger ● Submit a bug report / pull request – https://github.com/EFForg ● Respect users who send DNT header ● Help draft / adopt our DNT policy ● Donate to EFF! <location, date> We Still Need Better Tools ● Browser Improvements – Double Keyed Cookies – Harden browsers against fingerprinting – Better controls for blocking and clearing supercookies <location, date> We also need new business modles for the web ● Memberships ● Donations ● Crowd Funding ● Micropayments ● Non-Intrusive Advertising <location, date> Is advertising the best way to fund the web? It's hard to say. <location, date> But if we are going to live with advertising, it must stop violating users' privacy without their consent. <location, date> Thanks! Questions? [email protected] Twitter: @cooperq https://eff.org/privacybadger PGP: 75FB 9347 FA4B 22A0 5068 080B D0EA 7B6F F0AF E2CA.