Online document-security company IntraLink has signed a lease for 20,000 square feet of office space at The Schrafft Center at 529 Main St. in Charlestown.

IntraLink was represented by The Stevens Group of Boston. Flatley Co., The Schrafft Center’s owner, was represented in-house by William Bush.

The 650,000-square-foot Schrafft Center features easy access to Interstate 93 and the MBTA’s Orange Line.