Dell Inc. said Tuesday that it is buying data-protection company Credant Technologies for an undisclosed sum.

The Round Rock, Texas company said the acquisition will strengthen its computing solutions and improve the manageability, reliability and security in its enterprise-computing portfolio.

Credant was founded in 2001 and is headquartered in Addison, Texas. Dell has a long-standing joint-development partnership with the company and uses its technology. The company's specialty is protecting and encrypting user and corporate data.

Dell said it has taken steps over the past three years to expand its security portfolio.

"Protecting critical information has only become more important as organizations globally struggle to protect their data in an ever more complex world," Bob Heard, CEO and founder of Credant, said in a statement. "Together, we will continue to focus on innovation and building value that result in beneficial outcomes for our customers."

Shares of Dell increased 31 cents, or 3 percent, to close regular trading at $10.56. They slipped 5 cents in after-hours trading.