VeriSign has snapped up network security researcher iDefense for US$40 million in cash.

iDefense provides early warning assessment of Internet security threats to a fairly select group of government and very large enterprise clients, said Chris Babel, vice president of Managed Security Services at VeriSign.

By acquiring the company, VeriSign hopes to be able to market the iDefense research products to a wider audience, while at the same time using data from VeriSign's security monitoring operations to bolster the iDefense research, he said.

The 45-person research company will retain the iDefense name, but will operate as a division within Babel's group, he said. VeriSign has no plans to move the iDefense team from their present location, he said.

VeriSign's managed security services business provides managed firewalls, intrusion detection and vulnerability alerting under the VeriSign Managed Security Services brand.

Last year, VeriSign strengthened its position in this market by spending $135 million to acquire Guardent, a security services provider.