One of the world's most prominent cryptographers has issued a warning about a hypothetical incident in which a maths error in a widely used computing chip places the security of the global electronic commerce system at risk.

A professor at the Weizmann Institute of Science in Israel, Adi Shamir, circulated a research note about the problem to a small group of colleagues. He wrote that the increasing complexity of modern microprocessor chips was almost certain to lead to undetected errors.

The risk had been revealed by incidents such as the discovery of an obscure division bug in Intel's Pentium microprocessor in 1994, and more recently in a multiplication bug in Microsoft's Excel spreadsheet program, he wrote.