Privacy-Enhancing Technologies for Internet commerce

We examine privacy-enhancing technologies based on the consistency of the business plans, technology, stated objectives, and the concept of privacy as embedded in the technologies. Three distinct trust models result from the three distinct concepts of privacy: a right of autonomy, a right to seclusion and a right to property. We use these trust models to segment the privacy market and classify the privacy-enhancing technologies. The Anonymizer and Zero Knowledge's Freedom were built as technologies to enhance autonomy, while Privada Control, iPrivacy, and Incogno SafeZone are built to provide seclusion. Microsoft's Passport is built with an assumption of privacy as a tradable property right. Security, privacy, and authentication are intertwined and sometimes confused in the privacy market. We argue that the creation of new trusted third party is not an effective strategy. In the case of creating a trusted third party, autonomy-based products have been more successful than seclusion-based products, despite the wider array of services offered by seclusion services. Conceptions of Privacy Privacy is a critical element of trust (Camp, 2000; Boston Consulting Group, 1997). The extension of information is a canonical definition of trust in sociological experiments to determine trust in computer-mediated environment (e.g., Abric & Kahanês, 1972; Weisband & Kiesler, 1996). Privacy is an overloaded word. In order to examine the proposal for privacyenhancing technologies (PET), we begin with the fundamental understanding of privacy as three distinct rights: a right of autonomy, a right to seclusion and a right to property. (Camp, 2000 ) An understanding of these dimensions of privacy and the stakeholders in the privacy debates will illuminate the market for privacy in all its complexity. Privacy to some means Constitutional privacy rights and the United Nations' identification of privacy as a fundamental human right. Those who view privacy as a basic human right will not rely on the merchant to provide such privacy. (For the foundation-building article on privacy as a right see Warren, S. and L. Brandeis, 1890.) Consumers who see privacy as an absolute are likely to use customer-specific software to prevent the use of secondary information. However, shopping requires the provision of information: items selected, time of purchase, mechanism of payment, delivery address. Consumers who consider privacy a fundamental right may browse the web but are not likely to shop on the Internet until privacy-enhanced mechanisms of payment are available. Privacy to others means the right to be left alone. (For the definition of privacy as a tort, wee Prosser, 1941.) The second group, those who would avoid unwanted contact, is not entirely ∗ This work was funded in part by NSF CAREER Grant # 9985433.