Online Privacy Technologies Dr. Lorrie Faith Cranor AT&T Labs-Research NTIA Online Privacy Technologies Workshop

2 Why is Cathy concerned? Cathy March 1, 2000

3 How did Irving find this out? He snooped her He looked at the files on her computer He observed the “chatter” sent by her browser He set cookies through banner ads and “web bugs” that allowed him to track her activities across web sites

4 What do browsers chatter about? Browsers chatter about  IP address, domain name, organization,  Referring page  Platform: O/S, browser  What information is requested URLs and search terms  Cookies To anyone who might be listening  End servers  System administrators  Internet Service Providers  Other third parties Advertising networks  Anyone who might subpoena log files later

5 A typical HTTP request GET /retail/searchresults.asp?qu=beer HTTP/1.0 Referer: User-Agent: Mozilla/4.75 [en] (X11; U; NetBSD 1.5_ALPHA i386) Host: Accept: image/gif, image/jpeg, image/pjpeg, */* Accept-Language: en Cookie: buycountry=us; dcLocName=Basket; dcCatID=6773; dcLocID=6773; dcAd=buybasket; loc=; parentLocName=Basket; parentLoc=6773; ShopperManager%2F=ShopperManager%2F=66FUQULL 0QBT8MMTVSC5MMNKBJFWDVH7; Store=107; Category=0

6 What about cookies? Cookies can be useful  used like a staple to attach multiple parts of a form together  used to identify you when you return to a web site so you don’t have to remember a password  used to help web sites understand how people use them Cookies can be harmful  used to profile users and track their activities without their knowledge, especially across web sites

7 YOU Search engine Ad Search for medical information Book Store Ad Buy book With cooperation from book store, ad company can get your name and address from book order and link them to your search Read cookie Set cookie

8 Web bugs Invisible “images” embedded in web pages that cause cookies to be transferred Work just like banner ads from ad networks, but you can’t see them unless you look at the code behind a web page Also embedded in HTML formatted messages Can also use JavaScript to perform same function without cookies For more info on web bugs see:

9 Referer log problems GET methods result in values in URL These URLs are sent in the REFERER header to next host Example: name=Tom+Jones&address=here+there&cr edit+card= &PIN=1234& -> index.html

10 Low tech solutions Wander around cyber cafes Use free service instead of ISP Set up a pre-paid cash account with ISP  give all phony information Obtain unusual domain name and get people you trust as name servers Forge , spoof IP, etc.... And don’t give out any personally- identifiable data!

11 Types of software tools Anonymity and pseudonymity tools  Anonymizing proxies  Mix Networks and similar web anonymity tools Onion routing Crowds Freedom  Anonymous Encryption tools  File encryption  encryption  Encrypted network connections Filters  Cookie cutters  Child protection software Information and transparency tools  Identity management tools  P3P Other tools  Privacy-friendly search engines  Computer “cleaners”  Tools to facilitate access

12 Regulatory and self-regulatory framework ServiceUser The Internet Secure channel P3P user agent Cookie cutter Anonymizing agent

13 Anonymizing proxy Acts as a proxy for users Hides information from end servers Sees all web traffic Free and subscription services available Some free services add advertisements to web pages Proxy Browser End Server Request Reply

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15 Pseudonymity tools quote.com nytimes.com expedia.com mfjh asef dsfdf Proxy Automatically generate user names, passwords, addresses, etc. unique to each web site you visit username

16 CUSTOMER PC Public Identity Private Identity John DoeiPrivacyABCDEF 1 MAIN ST 1 dQg85xP26 Kansas City, KS iPrivacy private shipping labels WEB FORM Name : iPrivacy ABCDEF Address: : 1 dQg85xP26 City : Kansas City State : KS Zip : WEB e-Tailer Order Entry System Submit Credit Card If Authorized Ship Product Shipping Subsystem Input Private Identity Decode Address PRINT LABEL iPrivacyABCDEF 1 MAIN ST Kansas City, KS 11122

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18 Incogno SafeZone The merchant offers Incogno SafeZone from its site Upon checkout, the buyer enters personal information into The Incogno SafeZone – a separate server.

19 Incogno SafeZone Incogno reinforces that the purchase is anonymous. The anonymous purchase is complete with no added software installation or setup for the buyer.

20 Privada Multi-server design to shield real-world info Info is compartmentalized & encrypted, then processed by servers on a need-to-know basis Online identities and activity are kept distinct from real- world identities Patent-pending privacy management infrastructure

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22 B,kAkA CkBkB Mixes [Chaum81] Sender routes message randomly through network of “Mixes”, using layered public-key encryption. Mix A dest,msg kCkC CkBkB kCkC kCkC SenderDestination msg Mix C k X = encrypted with public key of Mix X Mix B

23 Freedom by Zero-Knowledge

24 Freedom nyms Create multiple psuedonyms Surf without a nym Select a nym and surf

25 Crowds Experimental system developed at AT&T Research Users join a Crowd of other users Web requests from the crowd cannot be linked to any individual Protection from  end servers  other crowd members  system administrators  eavesdroppers First system to hide data shadow on the web without trusting a central authority

26 Crowds illustrated Crowd membersWeb servers

27 Anonymous Anonymous r ers allow people to send anonymously Similar to anonymous web proxies Some can be chained and work like mixes

28 Encryption tools File encryption encryption  Many programs include encryption features built in or available as plug-ins  Web-based encrypted that self-destructs – Disappearing, Inc. Encrypted network connections  Secure socket layer (SSL)  Secure shell (SSH)  Virtual private networks

29 Disappearing, Inc.

30 Filters Cookie Cutters  Block cookies, allow for more fine-grained cookie control, etc.  Some also filter ads, referer header, and browser chatter Child Protection Software  Block the transmission of certain information via , chat rooms, or web forms when child is using computer  Limit who a child can or chat with

31 Identity management tools Services and tools that help people manage their online identities  Offer convenience of not having to retype data and/or remember passwords  Some let consumers opt-in to targeted advertising (permission marketing), sharing data with sites, etc. Some pay consumers for providing data  Some check for privacy policies before releasing data or require minimum privacy standards for participating sites Examples  AllAdvantage.com  DigitalMe  Enonymous  Lumeria  Persona  PrivacyBank.com

32 Consumer fills out Persona with personal information Consumer can decide how each field is shared with online businesses and 3 rd parties Persona

33 Allows user to accept or reject cookies while surfing Cookie Watcher tells users when cookies are being dropped P3P Viewer alerts user to site with valid P3P policy; allows comparison to user’s privacy settings Pop-up Menu PersonaValet A free toolbar Four views provide features that include Cookie Management, P3P reader, automatic log-in, form-fill, quick access to top sites, search engines & comparison capabilities

34 PrivacyBank.Com PrivacyBank bookmark

35 Infomediary example: PrivacyBank PrivacyBank bookmark

36 Platform for Privacy Preferences (P3P) Offers an easy way for web sites to communicate about their privacy policies in a standard machine-readable format  Can be deployed using existing web servers This will enable the development of tools (built into browsers or separate applications) that:  Provide snapshots of sites’ policies  Compare policies with user preferences  Alert and advise the user For more info see

37 Using P3P on your Web site 1.Formulate privacy policy 2.Translate privacy policy into P3P format  Use a policy generator tool 3.Place P3P policy on web site  One policy for entire site or multiple policies for different parts of the site 4.Associate policy with web resources:  Place P3P policy reference file (which identifies location of relevant policy file) at well-known location on server;  Configure server to insert P3P header with link to P3P policy reference file; or  Insert link to P3P policy reference file in HTML content

38 The P3P vocabulary Who is collecting data? What data is collected? For what purpose will data be used? Is there an ability to opt- in or opt-out of some data uses? Who are the data recipients (anyone beyond the data collector)? To what information does the data collector provide access? What is the data retention policy? How will disputes about the policy be resolved? Where is the human- readable privacy policy?

39 Transparency P3P clients can check a privacy policy each time it changes P3P clients can check privacy policies on all objects in a web page, including ads and invisible images

40 Microsoft/AT&T P3P browser helper object A prototype tool designed to work with Microsoft Internet Explorer Browser Not yet fully tested, still missing some features

41 Preference settings

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43 When preferences are changed to Disallow profiling, the privacy check warns us that this site profiles visitors

44 IDcide Privacy Companion A browser plug-in that adds functionality to Netscape or Internet Explorer browsers Includes icons to let users know that sites use first- and/or third-party cookies Enables users to select a privacy level that controls the cookie types allowed (1 st or 3 rd party) Prevents data spills to 3 rd parties through “referer” Lets users view tracking history Prototype P3P-enabled Privacy Companion allows for more fine-grained automatic decision making based on P3P policies

45 Searching for a P3P policy No P3P policy found P3P policy is NOT acceptable P3P policy is acceptable IDcide P3P Icons

46 Double clicking on the P3P icon indicates where the site’s policy differs from the user’s preferences

47 YOUpowered Orby Privacy Plus A tool bar that sits at the top of a user’s desktop and allows a user to  Accept or deny cookies while surfing  Decide how, when and where to share personal information  Store website passwords  Enjoy the convenience of "one-click" form-fill P3P features in prototype automatically rate web sites based on their P3P policies

48 Trust Meter

49 Orby cookie prompt

50 Orby preference setting menu

51 IBM P3P Policy Editor Allows web sites to create privacy policies in P3P and human-readable format Drag and drop interface Available from IBM AlphaWorks site:

52 Sites can list the types of data they collect And view the corresponding P3P policy

53 Templates allow sites to start with a pre-defined policy and customize it to meet their needs

54 PrivacyBot.com Allows webmasters to fill out an online questionnaire to automatically create a human-readable privacy policy and a P3P policy

55 YOUpowered Consumer Trust Policy Manager Wizard

56 Other tools Privacy-friendly search engines  TopClick Computer “cleaners”  Window Washer – removes all traces of what web sites you visited, what files you viewed, and what files you deleted Tools to facilitate access  PrivacyRight

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60 Tools work together P3P tools  help users understand privacy policies Seal programs and regulations  help ensure that sites comply with their policies Anonymity tools and filtering tools  reduce the amount of information revealed while browsing Encryption tools  secure data in transit and storage Laws and codes of practice  provide a base line level for acceptable policies

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