PortAuthority, the data leak prevention company, has raised $18 million more in venture backing. New investor New Enterprise Associates led the round. Existing investors Sequoia, Greylock, and Lexington Ventures also participated.

We talked with Kittu Kolluri, the NEA venture capitalist who made the investment and who sits on the Palo Alto company’s board. He said there are many competitors, including Vontu, Tablus and Reconnex, but that he chose to invest in PortAuthority because its ability to reduce “false positives” immediately impressed him. Upon installment, it wrongly flags “problem leaks” about 2 percent of the time, he said.

With Sarbanes Oxley and other regulations making it important for companies to control distribution of their information, the market is seeing significant growth.

Not sure how it would stop board members whispering secrets to the media, however, which is what got HP into trouble recently.