The government's new cyber-security officials yesterday asked telecommunications companies for help in building at government computer network that would have 'no risk of outside penetration' — a task some computer security consultants say is nearly impossible. Plans for the private network, called Govnet, hinge on whether a reliable network infrastructure can be built at an affordable price, officials said. Computer system consultants said they could not estimate how much the network would cost because of the government's enormous size and security needs. Richard Clarke, who was appointed special adviser to the president for cyberspace security this week, said he believes a more reliable system can be built. Ninety percent of available fiber-optic space is unused and fairly inexpensive to obtain, he said. Govnet is part of a plan Clarke announced earlier this week 'to secure our cyberspace from a range of possible threats, from hackers to criminals to terrorist groups, to foreign nations, which might use cyber-war against us in the future'. Govnet would be completely independent from the Internet to help keep out hackers and viruses, according to the government's plan. The request from the General Services Administration asks that telecommunications companies submit proposals about how the network could be built, how much it would cost, and how long it would take to construct. This year, the current network has been breached by hackers, computer worms and viruses. The system was also roughed up by the 'Code Red' computer worm and an attack program called 'I Love You'. The viruses affected thousands of government computers. Last year a report by the General Accounting Office, an internal government watchdog, found weaknesses in the computer network that could allow terrorists or hackers to 'severely damage or disrupt national defense or vital public operations or steal sensitive data'. Clarke said the government's current virtual private network is vulnerable to viruses and denial of service attacks that Govnet would make more difficult to execute. An internal network, such as the Govnet proposal, is worth investigating but will probably fall to sophisticated hackers, said Amit Yoran, chief executive of the security-services company Riptech Inc. and a former information-security program director at the Defense Department. 'It is probably more feasible to implement and strongly enforce global security postures and practices rather than go out and purchase new assets,' Yoran said. 'Once someone is able to get in, they will find a weak link. When you have a network the size of the government's there will be weak links. Someone will get in.' What is the Govnet?