MENLO PARK -- The threat is always there -- in your car, at the
office, on the table next to where you sleep at night: a near-
biblical plague of worms, phisher kings, identity thieves, even
cyberterrorists.  As computer networks have been transformed
into a global battlefield, where America faces what former
Defense Secretary Leon Panetta recently called a "cyber-Pearl
Harbor," security experts who understand those vast neural
systems have become prized recruits in an invisible war.   As
senior principal scientist in the computer laboratory at SRI
International, a nerd think tank, he and other brainiacs are
attempting to turn every computer and mobile device into a
fortress -- a firewall insurmountable by hackers. If Neumann can
pull it off, creating a safe computer platform will be the
crowning achievement of 60 years' work. "This is a chance, maybe
the only chance I'll ever see, to really pull together
everything that I've learned," he says. "Anything is within our
scope if it leads to something dramaticall