Dr. Walter W. Jacobs, 67, a professor emeritus of computer science at American University and a former cryptologist at the National Security Agency, died of cancer Feb. 11 at George Washington University Hospital.

Dr. Jacobs, who was born in Newark, N.J., graduated from the City College of New York and earned master's and doctor's degrees at George Washington University. He served in the Army in World War II.

He moved to this area in 1947 and worked for the Commerce and Air Force departments until 1961, when he joined the NSA as deputy chief of the office of research. In 1966, he was named head of the National Cryptologic School.

In 1969, Dr. Jacobs left the government and joined the faculty of AU, where he taught computer science until he retired in 1980.

He was a member of the Mathematical Association of America and other professional organizations. He also was a member of the Cosmos Club.

His first wife, Irene Ostreicher Jacobs, died last year. Survivors include his wife, Jean Cook Jacobs of Washington; his father, Harry S., and two sisters, Pearl Bilofsky and Natalie Abrams, all of New York City, and a brother, Morton C., of Haddonfield, N.J.