Translating privacy practices into privacy promises - how to promise what you can keep

Enterprises advertise privacy promises using the W3C Platform for Privacy Preferences (P3P). These privacy promises define what recipients can obtain what collected data for what purpose. Internally, enterprises can use fine-grained privacy practices such as defined by the Platform for Enterprise Privacy Practices (E-P3P) to enforce privacy. These internal privacy policies should guarantee and enforce the promises made to the customers. Since privacy practices reflect business internals, they can change frequently. As a consequence, it can be challenging to keep the promises up-to-date with the actual practices. To enable up-to-date privacy promises, we describe a methodology for enterprises to promise what they can keep. This is done by automatically transforming E-P3P privacy practices into corresponding P3P privacy promises that reflect the actual enterprise-internal behavior. These P3P promises can then be published on a regular basis. Whenever the internal policies change, the P3P promises can easily be updated as well.