ATLANTA, GA. — CipherTrust, a provider of messaging security solutions backed by Noro-Moseley Partners and other venture capital firms, is being sold.

Privately held CipherTrust, which was launched by technology entrepreneur Jay Chaudhry in March of 2000, is being acquired by Secure Computing Corporation in a deal worth $273.6 million.

Secure Computing (Nasdaq: SCUR) is based in San Jose, CA. The firm acquired CyberGuard in a $295 million deal last August.

The CipherTrust acquisition includes $185 million in cash, 10 million shares of Secure Computing common stock, and a $10 million note subject to performance goals. CipherTrust shareholders will own some 14 percent of Secure Computing once the deal closes.

Jay Chaudhry, the chief executive officer and chairman of CipherTrust, will become the chief strategy officer for Secure Computing. He also will become vice chairman of the firm’s board of directors.

Noro-Moseley, which is based in Atlanta, was one of five investors in CipherTrust. Others included Battery Ventures, Greylock, U.S. Venture Partners and Silicon Valley Bank. CipherTrust raised some $42 million in venture capital.

CipherTrust develops applications to secure messages from spam, viruses, unauthorized intrusions and phishing.

“We are excited to be joining forces with Secure Computing,” Chaudhry said in a statement. “This transaction brings together two very successful companies that together can redefine enterprise gateway security.

“The synergies between the two companies are tremendous,” he added. “Our products and technologies are complementary, our channel and selling strategy similar but with little overlap in channel partners, and our teams have strong domain expertise in security with an established record for delivering innovative products. Our combined business will bring focus and innovation of a start-up and the scale, size and financial strength of a larger company.”

CipherTrust is among the world leaders in selling secure content management appliances.

Secure Computing is focuses on unified threat management, web filtering and hardware authentication.