Privacy Policy, Law and Technology Carnegie Mellon University Fall 2007 Lorrie Cranor 1 Privacy Policy Management October 11, 2007

Privacy Policy, Law and Technology Carnegie Mellon University Fall 2007 Lorrie Cranor 2 Privacy & security policy management Today many organizations have ad hoc policies Difficult to enforce reliably Policy management frameworks promote consistent policy enforcement Components Policy authoring Policy conflict/gap detection/resolution Policy enforcement Policy communication Policy composition and comparison (combining multiple policies)

Privacy Policy, Law and Technology Carnegie Mellon University Fall 2007 Lorrie Cranor 3 Privacy languages serve many roles Specify organization’s privacy policy to end users and their agents Specify users’ privacy preferences to users’ agent Specify organization’s privacy policy to gatekeeper server that can approve or deny requests to access database Specify policy associated with particular data elements to parties that buy or rent data

Privacy Policy, Law and Technology Carnegie Mellon University Fall 2007 Lorrie Cranor 4 Can one privacy language do it all? Maybe… But so far none have emerged We’ve found over a dozen privacy languages (including several access control and rule languages used for privacy applications) Languages have different audiences, specify policies at different levels of granularity, and have different strengths and weaknesses

Privacy Policy, Law and Technology Carnegie Mellon University Fall 2007 Lorrie Cranor 5 Privacy Languages A P3P Preference Exchange Language (APPEL) Alliance Identity - Web Services Framework (ID - WSF) Customer Profile Exchange (CPExchange) Declarative Privacy Authorization Language (DPAL) Enterprise Privacy Authorization Language (EPAL) eXtensible Access Control Markup Language (XACML) GEOPRIV Platform for Enterprise Privacy Practices (E-P3P) Platform for Privacy Preferences (P3P) Privacy Rights Markup Language (PRML) Privacy Template Security Assertion Markup Language (SAML) XML Access Control Language (XACL) X-Path Based Preference Langauage (XPref)

Privacy Policy, Law and Technology Carnegie Mellon University Fall 2007 Lorrie Cranor 6 Genealogy of languages

Privacy Policy, Law and Technology Carnegie Mellon University Fall 2007 Lorrie Cranor 7 EPAL Enterprise Privacy Authorization Language Developed by IBM, submitted to W3C Allows enterprises to develop granular rules to check whether data access is authorized Similar to P3P syntax but not identical Includes Data-categories User-categories - administrators, doctors, etc. Purposes Actions - disclose, read, etc. Obligations - delete after 30 days, get consent, etc. Conditions - user category = doctor Allow and deny rules

Privacy Policy, Law and Technology Carnegie Mellon University Fall 2007 Lorrie Cranor 8 User privacy preferences P3P 1.0 agents may (optionally) take action based on user preferences Users should not have to trust privacy defaults set by software vendors User agents that can read APPEL (A P3P Preference Exchange Language) files can offer users a number of canned choices developed by trusted organizations Preference editors allow users to adapt existing preferences to suit own tastes, or create new preferences from scratch For more info on APPEL see or Chapter 13 in Web Privacy with P3P

Privacy Policy, Law and Technology Carnegie Mellon University Fall 2007 Lorrie Cranor 9 Microsoft privacy template language See Appendix D of Web Privacy with P3P ty/privacy/overview/privacyimportxml.asp ty/privacy/overview/privacyimportxml.asp Specifies rules for user agents to handle various types of cookies Based on P3P compact policy tokens Allows policies for specific web sites

Privacy Policy, Law and Technology Carnegie Mellon University Fall 2007 Lorrie Cranor 10 Microsoft example <site domain=" action="accept">

Privacy Policy, Law and Technology Carnegie Mellon University Fall 2007 Lorrie Cranor 11 APPEL rule <appel:RULE behavior="limited" prompt="yes" description="Warning! Data may be shared."> Behavior - request - block - limited description connective - or - and - non-or - non-and - and-exact - or-exact pattern

Privacy Policy, Law and Technology Carnegie Mellon University Fall 2007 Lorrie Cranor 12 What does this APPEL ruleset do? <appel:RULESET xmlns:appel=" xmlns:p3p= crtdby="Lorrie Cranor" >

Privacy Policy, Law and Technology Carnegie Mellon University Fall 2007 Lorrie Cranor 13 Creating APPEL rule sets Express your personal privacy preferences in English Example: "I don't want companies to share my data." Translate your rules into P3P vocabulary elements Example: "RECIPIENT=ours" Create an APPEL ruleset that represents your privacy preference rules (plus a catch- all rule)

Privacy Policy, Law and Technology Carnegie Mellon University Fall 2007 Lorrie Cranor 14 Using APPEL to analyze P3P policies Toolkit for Automated Privacy Policy Analysis (TAPPA)

Privacy Policy, Law and Technology Carnegie Mellon University Fall 2007 Lorrie Cranor 15 Homework 3 Discussion ch-fa07/hw/hw3.html ch-fa07/hw/hw3.html Web bugs - What are they used for? Do these uses raise privacy concerns? P3P user agent critiques