The open-end argument for private computing

Abstract

A truly personal machine, called a private machine and implemented as a Personal Digital Assistant (PDA), is fundamentally different from traditional machines. It is personal and private in an unprecedented manner, and its modus operandi is such that network and power failures will not be rare. Designing distributed systems where PDAs are treated as “first class citizens” is a challenge. Furthermore, private assets (electronic money, keys for authentication and opening doors) will be stored in PDAs. Ownership and control of these assets and the media that store and communicate them should remain with the user. This must be reflected in the design of systems for private computing. We introduce the “open-ended argument” to describe the design strategy we used for designing a system that is designed to reveal information to the user (as opposed to hide it). We argue and show that when systems are designed this way, the user (a human) is better able to control the system and his personal data, as he can make better decisions than the system itself based on qualitative assessment of the provided information. The system we have designed and implemented under this design guide-lines is presented and discussed.