Colonel Frank Herrelko reported to NSA in 1953 as Assistant Director for Communications Security, the predecessor to what is now known as Information Assurance. Although many of its concepts had long existed, communications security (COMSEC) was still relatively new as a broad national concern.

Colonel Herrelko negotiated with the military services and Intelligence Community officials to establish formal authorities for national COMSEC activities. The resultant agreement became a charter recognizing the Director of NSA as the national COMSEC leader. It also created consolidated COMSEC production, distribution, and accountability systems for the nation. This agreement remained in place for two decades, until changes in technology necessitated changes in the community's COMSEC structure.

Under Colonel Herrelko's leadership, crucial changes to the design and construction of COMSEC equipment were implemented to meet new requirements and new conditions of use.

After retiring from the Air Force in 1967, Frank Herrelko returned to NSA as a special assistant to the chief of Research and Development. He helped to upgrade R&D personnel policies and to institute high-level recognition for many kinds of achievement in the field, including blue collar work, which significantly boosted organizational morale.

Colonel Herrelko retired from NSA in 1975 and served as a consultant through 1980. His lasting legacy will be that of pro-active leadership that laid the foundation for what has evolved into NSA's information assurance mission.