But people like Finisterre, who don't fit the traditional mold of buttoned-down engineer, are playing an increasingly important role in the effort to lock down the machines that run the world's major industrial systems. Finisterre is a white-hat hacker. He prods and probes computer systems, not to break into them, but to uncover important vulnerabilities. He then sells his expertise to companies that want to improve their security.

Two years ago, Finisterre, founder of security testing company Digital Munition, found himself swapping emails with a staffer at Idaho National Laboratory's Control Systems Security Program, a project funded by the U.S. Department of Homeland Security that is the first line of defense against a cyberattack on the nation's critical infrastructure.

Finisterre caught the attention of INL in 2008, when he in the CitectSCADA softwareused to run industrial control environments. He'd heard about the INL program, which helps prepare vendors and plant operators for attacks on their systems, and he thought he'd drop them a line to find out how good they really were.

He was not impressed.

Is INL already working with the hacker community? Finisterre wanted to know. He received an off-putting response. The term "hacker" denotes a person of a "dubious or criminal nature" who would "not be hireable by a national laboratory," an INL staffer told him via email.