You may or may not have picked up the news that Estonia came under cyber-attack in early May. Cyber attacks—usually consisting of multiple denial of service attacks—are pretty bloodless really. You don't see buildings reduced to piles of rubble or dead bodies strewn across the street. There's nothing to take photos of. There's only economic damage; web sites that cannot be accessed and transactions that cannot take place.

That's how it was when a Russian invasion force consisting entirely of digital signals marched across the border into Estonia in very large numbers and shut down the main Estonian bank. They also choked off a fair number of Estonian government web sites. The almost unanswerable question is whether it was the Russian government that launched the attack or whether it was Russian hackers. Estonia—it seems—provoked the attack when the Estonian government removed a statue (in Tallinn) that commemorates Soviet troops who were killed fighting the Nazis.

Estonian officials claim that some of the attacking computers had Kremlin IP addresses but—and I'm sure the Russians would suggest this—such computers could have been infected by viruses and used as bots by Russian hackers. That's what you call plausible deniability. There are spontaneous cyber attacks provoked by events. For example, in the Salt Lake City Winter Olympics Games, Apolo Ohno won the gold medal in the 1,500-meter speed-skating race when South Korean Kim Dong-Sung was disqualified. A denial of service attack that hit several US based servers followed.

Nevertheless most governments have "cyber soldiers" ready to engage in cyber warfare and it's quite likely that some of the incidents that are reported as hacker activity are government cyber soldiers out on exercise. Only Russia and China have an official branch of the armed forces devoted to cyberwarfare, but whenever any military activity or even military tension occurs cyber warfare breaks out. It happened first in the disintegration of Yugoslavia. It happened between India and Pakistan and more recently in the Middle East—where it is happening at a low level most of the time anyway, but the activity increases when the bullets fly.

The problem with cyberwarfare is that normal business activity suffers the collateral damage. There have been two attempts to completely take out the Internet—by mounting denial of service attacks on the 13 root servers that run the Internet DNS. One took place in 2002 and one took place in February of this year. These attacks weren't successful but they may not have been intended to be. They could have been mounted by one government or another simply as target practice in order to assess the amount of power that would be needed to be successful. No-one seems to know who was responsible.

The world is in urgent need of technology that can properly block denial of service attacks. There are some intrusion prevention systems and DOS mitigation products from the likes of Cisco, Top Layer, RADirect and others that can help but the cost is high. In any event they do not address the fundamental problem—that the Domain Name System itself is vulnerable. The only DNS product I'm aware of that can actually deflect a DOS attack completely is the DNS server from Secure64. But it has only just been released and even if the take-up is high, it is unlikely that even a small portion of the millions of DNS servers already deployed will be replaced by this product.

It's a sobering thought that the Internet, which was originally designed to survive a nuclear attack, has itself become a potential battleground. I came across a statistic in a Symantec security bulletin which made me think. Apparently 20 percent of the bots that are responsible for a variety of cybercrimes are located in China. Think about it. That's the wrong percentage. It's far too high. China may have the second largest market in the world for PCs, but it still amounts to less than 10 percent of worldwide shipments. PCs get to be bots by virus infection mostly—so how could it be that such infection is dramatically more common in China? It seems very unlikely.

An alternative explanation is that China's cyber soldiers get involved in a much greater number of "military exercises" than those from any other country.