Large databases do not adequately protect sensitive personal information according to a statistics professor in the US who says that individuals can still be identified despite attempts to anonymise them.
George Duncan is a statistics professor at Carnegie Mellon University in Pittsburgh, Pennsylvania. He writes in the journal Science that traditional methods of anonymising people's database records are not good enough.
He said that databases "de-identify" people by masking important information such as their Social Security number or their birthday, but that this does not render them unidentifiable. Anyone who can access more than one characteristic of a person in a database has a chance at identifying the person, he said.
The problem is that the very information that most closely identifies a person is likely to be that in which the organisation behind the database is interested, he wrote, meaning that it cannot be deleted or masked.
"The question is, how can data be made useful for research purposes without compromising the confidentiality of those who provided the data?" Duncan said in a statement.
Duncan said that it would be possible to build systems which make this kind of identity reconstruction impossible. He also said that further user-specific restrictions on the use of information in databases would go some way to solving the problem.
It is, said Duncan, a difficult problem to solve. "Achieving 'adequate' privacy will require engineering innovation, managerial commitment, information cooperation of data subjects and social controls (legislation, regulation, codes of conduct by professional associations and response to reactions of the public)," Duncan wrote in Science.
As public and private bodies gather increasing amounts of information on customers and citizens, concern is growing about individuals' rights to privacy within such systems. Some opposition to the Government's identity register is based on fears about the abuse of or errors in the database that would lie behind any ID card.
Privacy watchdog the Information Commissioner has warned that the UK is becoming a surveillance society without adequate privacy safeguards, and the House of Lords earlier this year said they would probe the constitutionality of such widespread surveillance.