To keep messages secure, the computers that run wireless networks must do some complicated math to authenticate every Internet-enabled cell phone or wireless personal digital assistant that contacts them, and the devices must do the reverse, which can tax their batteries. Sun Microsystems senior staff engineer Hans Eberle and his team at Sun Labs are addressing that problem by creating a microprocessor that can be plugged into network computers to quickly authenticate messages from a range of wireless gadgets. The numerical "keys" used to authenticate most electronic messages today are generated by multiplying prime numbers; but to foil hackers, these numbers must be very large, containing up to 1,024 digital bits. Eberle uses a technique called elliptic-curve cryptography that instead derives keys from complex geometrical curves. The complexity of the curves makes the keys more difficult to break, so the same level of security can be achieved with smaller keys that require less computation to use. Eberle's chips can establish secure connections at the rate of 7,000 per second-the "fastest reported," he says. Sun's product groups are evaluating the microprocessors for inclusion in the firm's server computers.