Making 'Big Brother' obsolete.

Making "Big Brother' obsolete

As computer systems proliferate, more and more organizations routinely exchange information about individuals. People are losing the ability to control the way information about them is used. Moreover, they have no way of knowing if the information is inaccurate, obsolete or inappropriate. "The foundation is being laid for a dossier society, in which computers could be used to infer individuals' life-styles, habits, whereabouts and associations from data collected in ordinary consumer transactions,' says David Chaum of Amsterdam's Center for Mathematics and Computer Science in the Netherlands.

In the October COMMUNICATIONS OF THE ACM, Chaum outlines a scheme that he says effectively solves the problem by protecting privacy and maintaining security for both individuals and organizations. In Chaum's novel approach, an individual uses a different account number or "digital pseudonym' with each organization --a credit card company, retail store, the government, or whatever. Although pseudonyms, created by a special random process, can't be linked, businesses like banks would still be able to ensure that transactions are legitimate.

Present systems also emphasize the one-sided security of organizations attempting to protect themselves from individuals, says Chaum. His scheme allows all parties to protect their own interests. It relies on individuals keeping secret, cryptographic keys from organizations and organizations devising other secret keys that are kept from individuals. During transactions, parties use these keys to provide each other with specially coded confirmation of transaction details--but no further information that could be used for other purposes.

Unlike current systems, in which organizations issue and usually control the use of "tokens' like plastic cards with magnetic strips or embedded microcomputers, individuals would have their own "personal card computers.' Such a credit cardsized computer would keep the necessary records and provide the needed pseudonyms and secret keys. "These card computers,' says Chaum, "are already technically feasible.'

Individuals stand to gain increased convenience and reliability and improved protection against abuses by individuals and organizations--a kind of parity with organizations, says Chaum, "and, of course, monitorability and control over how information about them is used.'