Existing backer Google Ventures has returned for the authentication service provider's latest round, which boosted its overall funding to $48m.

US-based cloud-based authentication services provider Duo Security obtained $30m yesterday in a series C round featuring Google Ventures, the corporate venturing arm of internet company Google.

The round was led by venture capital firm Redpoint Ventures, with Benchmark, Radar Partners and True Ventures also participating.

Duo Security offers a two-factor authentication security platform, providing the service to some 5,000 companies.

Two-factor authentication is a security feature whereby a code is sent to the user – via a smartphone app, by…