SAN FRANCISCO -- RSA Conference 2011 -- A Microsoft executive here today elaborated on his proposed concept of a "collective defense" as a way to combat the botnet threat against client machines.

Scott Charney, corporate vice president for Trustworthy Computing, late last year first called for requiring end user machines to get a health check to gain Internet access, and for quarantining sick or infected machines.

"Simply put, we need to improve and maintain the health of consumer devices connected to the Internet in order to avoid greater societal risk. To realize this vision, there are steps that can be taken by governments, the IT industry, Internet access providers, users, and others to evaluate the health of consumer devices before granting them unfettered access to the Internet or other critical resources," he said in a blog post last October.

But in his keynote address here at the RSA Conference 2011 today, Charney said he no longer thinks ISPs should have to quarantine sick machines due to privacy, safety, and emergency concerns. "It is important that solutions be developed that promote a healthy Internet without limiting its utility, much like a cell phone may require a password, but still allow emergency calls to be made even without that password," he said in a blog post today.

Collective defense could mean users getting trusted health certificates for their machines that could be used when they conduct online banking, for example, according to Charney.

Both the public and private sectors should create a proposal for a global Internet health model using existing technology, he said: "We are seeing a growing alignment of social, political, and economic factors. The time is right for industry, governments, and individuals to focus on Internet security and privacy to help drive progress toward a safer Internet.

"As the number of reported cybercrime victims grows, protection becomes not just an individual concern, but more of an ecosystem or societal concern."

Jeff Jones, director of Trustworthy Computing at Microsoft, says the collective defense concept would parallel the healthcare system by identifying sick people with a systematic approach to getting them healthy. "There are standards you follow and a complementary approach of getting exercise, taking your vitamins, and getting regular checkups. Systematically doing this promotes better health," Jones says.

Thus, network access control and other scans would check whether the client machine is following a company's, or bank's, policies for patching software and maintaining antivirus updates, for example, he says. "It's about promoting health," he says. "And also protecting user privacy."

Microsoft's Jones says one example would be a bank checking a user machine's "health": "It could be through banking software built into the browser," he says. That's just one way this model could be deployed, he says.

But Pedro Bustamante, senior research adviser for Panda Security, says this model isn't the answer. "You can't expect a consumer machine to be clean -- it may be clean of all known malware, but knowing all of the unknown malware is impossible, so this is not a good solution," Bustamante says.

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