DoS attack could shut down the net

Denial of service attacks are growing faster than bandwidth is being added to the internet, according to VeriSign, the company that administers the dot-com domain.

Criminal groups selling services online are increasingly threatening the fabric of the internet, as the size of the compromised networks of computers they control increases, VeriSign said.

The company claimed that a successful denial of service (DoS) attack against VeriSign could bring down the internet. Ken Silva, VeriSign's chief security officer, said: "There are attacks attempting to shut down our servers. This would effectively shut down the internet."

Silva said that although DoS attacks are difficult to trace, there are "a couple of well-known groups in Russia, China and Romania" that may be acting with their government's knowledge. "It would be hard to imagine groups who have this much activity going unnoticed by their governments," he said.

He said VeriSign "hoped to get smarter" in blocking malicious traffic: "We can continue to add bandwidth but ultimately, 20 years down the road, this can't continue as a foot race. The internet as a whole has to get smarter in denying DoS attacks."

VeriSign is currently upgrading its infrastructure in a scheme called Project Titan. This has included adding bandwidth but it is also monitoring its systems more closely.

Silva said: "Our monitoring systems now resemble those for the space shuttle. We monitor the capability of our CPUs and memory allocation on all of our servers. We're predicting what problems will occur rather than waiting for them to occur."

Many public sector organisations in the UK suffer from DoS attacks. The Probation Service has upgraded its servers in the past week to cope with the traffic created by botnets, according to one if its security managers.

The security manager said: "We've had to upgrade our hardware in the last week to cope with an unexpected increase in the volume of malicious traffic at the network gateway. Simply coping with that is compromising our ability to run our business. The problem is simply coping with what is coming at us."

Tim Pickett, a former technical security analyst at AOL, said ISPs should monitor their networks to mitigate DoS attacks, adding: "More should be done to tackle the problem on the ISP side."

Tom Espiner writes for ZDNet UK