Thomas Reilly

THOMAS REILLY has served as ArcSight’s Chief Executive Officer since September
2008 and as President since August 2007. Mr. Reilly served as Chief Operating
Officer from November 2006 to September 2007. From April 2004 to November 2006,
Mr. Reilly served as Vice President of Business Information Services of IBM.
From November 2000 until its acquisition in April 2004 by IBM, Mr. Reilly served
as Chief Executive Officer of Trigo Technologies, Inc., a product information
management software company. He holds a B.S. in mechanical engineering from the
University of California, Berkeley.