Michael A. Harrison

Michael A. Harrison (

In the 1960s, he worked with Sheila Greibach, Gene Rose, Ed Spanier, and Joe Ullian in a research group formed and led by Seymour Ginsburg, dedicated to formal language theory and the foundations of Computer Science. The work that came out of this group distinguished Computer Science theory from other fields. It also brought the field of formal language theory to bear on programming language research.

In 1975, he developed the HRU security model (named after its authors Harrison, Ruzzo, Ullman), an operating system level computer security model dealing with the integrity of access rights in the system.

With his Ph.D. student Pehong Chen at Berkeley, he founded the "Gain Technology" company (acquired by Sybase in 1992).

After retirement in 1994, he served as professor emeritus and also professor in the graduate school at Berkeley.