Private equity firm Thoma Bravo LLC has acquired Crossbeam Systems Inc., a security provider, for an undisclosed amount.

Crossbeam, headquartered in Boxborough Mass., provides software and hardware security.

In October, Thoma Bravo acquired software company Deltek Inc. for $1.1 billion.The Chicago firm also announced plans to buy Mediware Information Systems Inc. (Nasdaq: MEDW) for $195 million in September.