Apple Computer co-founder and philanthropist Steve Wozniak speaks in San Francisco, California, on February 1. US national security leaders and top cyber warriors from around the world are gathering here to plot defenses against criminals and spies that increasingly plague the Internet.

US national security leaders and top cyber warriors from around the world are gathering here to plot defenses against criminals and spies that increasingly plague the Internet.

Homeland Security Secretary Janet Napolitano and White House Cyber Security Coordinator Howard Schmidt will take part in this week's RSA conference along with computer defense companies and technology icons such as Apple co-founder and Craigslist creator Craig Newmark.

"We have before us more data moving into the cloud and more sophisticated ," said Qualys chief executive Philippe Courtot, who is among the keynote speakers at the premier event that kicks off on Monday.

"We need corporations, government and community working closer together."

Social networking and applications being hosted as services in the Internet "cloud" are among hot Internet trends presenting opportunities for hackers and challenges for those guarding networks.

Gone are the days when protecting computers meant building virtual fortress walls to keep attackers out and then hunting down software viruses by simply matching codes to lists of known offenders.

Conference topics will include finding ways to let workers visit online or let employees or partners access business networks safely from distant spots without opening computers to infections.

Legitimate websites must remain vigilant against being booby-trapped by hackers.

Computer defenses have broadened to include automated systems on constant watch for suspicious behavior, such as online bank account log-in information being entered faster than humanly possible.

Cyber crooks use programs that enter data quicker than fingers can type.

Organized crime and espionage themes promise to dominate at RSA, in part thanks to a slick online assault on and the recent discovery of some 75,000 computers worldwide woven into a "Kneber " by malicious code.

"Malware has become important as the sophistication of the attacks has increased," said Courtot, whose company was founded in France in 1999 and later moved to California.

"That is underscored by the Google Aurora attack. Now we know for a fact more than a hundred companies were compromised in very targeted attacks of industrial espionage," Courtot said.

FBI chief Robert Mueller will detail cyber threats ranging from identity theft to how extremists and hostile foreign powers abuse the Internet.

Former Secretary of Homeland Security Michael Chertoff and Richard Clarke, former chief counter-terrorism adviser at the National Security Council, will discuss dealing with cyberspace threats "without creating Big Brother."

Napolitano is to focus on how online threats hit society. Schmidt will take part in a "town hall" talk.

Technology firms ranging from big guns such as Microsoft, Cisco, IBM, Symantec will join smaller cyber warriors specializing in fields including biometrics, encryption, and online behavior.

"There are so many security topics high on the agenda," Cellcrypt chief executive Simon Bransfield-Garth told AFP.

"Certainly one of the topics is how mobile devices are becoming more like computers with the benefits and drawbacks as well."

A organization recently released online open-source computer code for capturing mobile telephone conversations, according to Bransfield-Garth, whose company specializes in smartphone defenses.

RSA is expected to be rife with releases of studies highlighting threats, and rich with launches of products or services pitched as defensive weapons.

Startup XyberSecure will challenge those gathered to hack into a website to prove the prowess of its "behavior-based" security.

RSA was created in 1991 for cryptographers to share advances in Internet security but has evolved with the times, according to conference general manager Sandra Toms LaPedis.

"Our mission to drive the worldwide information security agenda," LaPedis said.