While popular email services such as Gmail and Outlook aren’t likely to suffer a large-scale data breach, individual inboxes can still be compromised in a myriad of other ways that present just as big of a threat. To mitigate that risk, a fast-growing startup, Virtu Inc., raised $29 million today from a group of top investors led by Bessemer Venture Partners.

The funding tops off two years that saw over 4,000 organizations sign up for Virtu’s email security service, which employs a technology called Trusted Data Format (TDF) to protect messages from prying eyes. It was developed by co-founder Will Ackerly during his time at the NSA to help protect sensitive government data and works by placing every file in a sort of digital lockbox that can only be controlled by the sender. The software makes it possible to ensure that emails are only accessible to their intended recipients, update usage rights as needed and even set a self-destruction timer if the contents of a message are particularly sensitive.

It’s more or less the same concept that Vera Inc. and Bitglass Inc. have implemented in their security services, except they focus on a much broader range of areas than just email privacy. Virtu said that today’s funding will help widen its value proposition as well by financing the development of “new products to protect all types of data,” a statement that can be interpreted in two ways. The startup could be planning to create value-added offerings to complement its service, or it may simply want to make the platform’s core encryption and access control functionality available in more forms.

Virtu is currently available for Gmail, Google Drive, Microsoft Outlook and Yahoo Mail. The outfit also offers a set of SDKs and APIs designed to let third party developers integrate its service’s capabilities into their software, a part of its business that the new funding will help bolster as well. And last but not least, Virtu will scale worldwide operations in a bid to win over more international clients.

The startup is targeting organizations in a wide range of segments ranging from entertainment and manufacturing to regulated industries like financial services, where the need to protect sensitive data is accompanied by strict compliance obligations. Having the ability to individually control who can access internal emails helps address both requirements. And Virtu claims that its service can accomplish all this without hampering user productivity as traditional security tools are prone to do.

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