The Office of the E-Envoy has signed a deal with security specialist Entrust to build the infrastructure supporting the National Root, a key security facility at the heart of the e-government agenda.
E-envoy Andrew Pinder predicted the deal would boost the delivery of online services.
"This announcement represents a giant leap forward in our plans to deliver online public services in ways that will enable users to interact with government securely in places and at times that are convenient to them," he said.
A core component of the government's strategy for making services available electronically by 2005, the National Root underpins security systems that authenticate and encrypt transmissions within government.
A spokesman for the Government Communications Headquarters (GCHQ) described the National Root as "the ultimate trusted third party" for authenticating messages across government.
GCHQ's information assurance division, the Communications-Electronics Security Group (CESG) will host and operate the National Root.
Officials expect the National Root will boost public confidence in dealing with the government electronically. John Doody, head of Infosec Customer Services at CESG, said, "The creation of the National Root means that we now have the means to win the trust and confidence of every user."