LAS VEGAS - In a contentious keynote speech that created an uproar at the Black Hat Briefings security conference here yesterday, security researcher Marcus Ranum charged that the full disclosure of software vulnerabilities isn't improving computer security. Instead, Ranum said, it only encourages attacks by what he called "armies of script kiddies."Many security experts and corporate users believe that publicizing software flaws will improve security by forcing software vendors to improve the quality of their products and to quickly fix potentially damaging bugs - a point that was reiterated by several audience members and other speakers at the Black Hat conference.But Ranum, CEO of security software vendor Network Flight Recorder Inc. in Rockville, Md., argued that neither of those things is happening. Declaring a "call to arms to change how we perceive security," Ranum took aim at the practice of posting detailed information about software flaws and security holes on the Internet.Thus far, even with all that information being made available, there hasn't been "an appreciable impact" on the turnaround times for fixing bugs after they have been reported, Ranum said. He asked the audience, "If full disclosure is working, why isn't the state of security improving?"Ranum claimed that many disclosures of security holes are "rock-throwing" incidents done by companies or individuals to attack vendors such as Microsoft Corp. or for the purposes of self-promotion, financial gain or ego gratification. And, he said, such disclosures give malicious attackers point-and-click tools that they can use to take down Web sites.There are better ways to publicize software vulnerabilities than by releasing the information to the public, Ranum added. For example, he said, an increasing amount of software is becoming available with auto-update capabilities that could allow bug fixes and patches to be streamed directly to users.But other attendees at the Black Hat conference - an annual precursor to the Defcon hackers convention that features sessions aimed at corporate users - said they're skeptical that limiting the disclosure of vulnerability information would benefit companies.Mudge, a vice president at Cambridge, Mass.-based security consulting firm @Stake Inc. who uses only one name, rejected what he called the "metered dissemination of information" about potentially damaging security holes. While the number of exploits by so-called script kiddies and other attackers has increased, widespread publicity about the incidents have helped to raise security awareness in the business community, he said.As much vulnerability information as possible should be disclosed in hopes that responsible users will employ it to protect their companies from being attacked, Mudge added. "If I took that [information] away from you, you wouldn't be able to defend your system," he said.Other attendees seconded Mudge's comments. "How do you give information to people [so they can] manage risk without giving it to other people?" asked Eric Pulaski, chairman and chief technology officer at BindView, a Houston-based security consulting firm. "If the information and the tools aren't there, [companies] can't protect themselves."And Sean Wray, an Internet security engineer at Kana Communications Inc. in Redwood City, Calif., said he doubts people could ever be stopped from distributing information about software holes and other security vulnerabilities.Bruce Schneier, CTO at Counterpane Internet Security Inc. in San Jose, offered a different perspective on the growing challenge of securing systems during another keynote speech at the conference yesterday. Schneier said software is becoming more insecure because of the increasing complexity of products such as Windows 2000. "Increased complexity means increased errors," he said.But Ranum insisted that poor security can be traced more to excessive disclosure than lack of resources or complex code. "We Americans have a lot of freedom of speech, but unfortunately we tend to execute [it] irresponsibly," he said. "And freedom of speech in computer security has created this huge gray area for people to carry out irresponsible activities."At the end of his speech, Ranum urged attendees to turn their attentions from trying to find holes in software to building better defensive strategies for besieged users. "The Huns didn't know how to build Rome; they just knew how to sack it," he said. "Just show us that you have useful stuff [instead of] destroying other people's stuff.