In a dimly lit room off the main drag of a computer security conference, programmers guzzle drinks and wolf pizza while methodically hunting for cryptic messages hidden in the bowels of enemy territory.
They are looking for long strings of numbers and other clues that contest organisers have embedded within servers, the giant computers that perform critical tasks such as processing credit card transactions and granting employees remote network access.
"There are more castle walls to defend, and each one is vulnerable to a different cannon ball," says Jason Spence, 26, a network security consultant donning a red fedora and blue tie during Defcon, one of the world's most important conferences for hackers, computer security professionals and government agents.
About 6,000 computer aficionados gathered at the annual three-day event in Las Vegas, which concluded on Sunday. More than 500 contestants competed in capture the flag and 16 other Defcon games, considered a legal talent show for hackers — a way to show corporations, consumers and government agencies how vulnerable their networks are.
"The ability to do something that's socially unacceptable is always a thrill," says Chris Eagle, a computer science professor at the Naval Postgraduate School in Monterey, Calif. Several rooms away, 17-year-old Dan Beard is readying a robot that took him four months to design.
The machine shoots pellets using a camera that can see all of its 30 targets, which are the size of 50-cent pieces situated about 10 feet away. Most competing robots are equipped with cameras that can see only a fraction of the targets.
"I might not be the fastest, but I'm definitely going to hit most of them down," says Beard, a high school student in Newport Beach, California. Other games include a lock-cracking tournament, where contestants armed with picks compete to be the first to open a door protected by a padlock, dead bolt and doorknob lock.