OP-20-G
OP-20-G was the name of a special working group of the US Navy so the Navy of the United States of America , whose main task during the time of World War II in the cryptanalysis and signal intelligence was. OP-20-G is the abbreviation for "Office of Chief of Naval Operations (OPNAV), 20th Division of the Office of Naval Communications, G Section / Communications Security" . The headquarters were in the Navy Department building in the American capital Washington .
The main tasks of this working group the observation were deciphering and evaluating the enemy Marine - radio communications , particularly the anti-war Japan , Italy and Germany . For example, the OP-20-G was able to achieve success against the secret German submarine radio traffic encrypted with the help of the Enigma-M4 key machine , whereby special electromechanically operated cryptanalytic machines such as “ Duenna ” were developed and used. The secrecy within this group was stricter than when the atom bomb was built .
Due to the experience that the Americans gained with the fragmentation of their cryptanalytic services in World War II, especially because of the competition between the Navy and the Army , the OP-20-G was absorbed into the newly established National Security Agency (NSA) after the war .
literature
- Friedrich L. Bauer : Deciphered Secrets. Methods and maxims of cryptology. 3rd, revised and expanded edition. Springer, Berlin a. a. 2000, ISBN 3-540-67931-6 .
Web links
- OP 20 G takes over the deciphering of the submarine radio traffic
- OP-20-G Staff Memorandum. Formerly secret document about the organization, 1944, PDF; 14.1 MB (English), accessed November 30, 2018.
Individual evidence
- ↑ Friedrich L. Bauer: Deciphered secrets. Methods and maxims of cryptology. 3rd, revised and expanded edition. Springer, Berlin a. a. 2000, p. 433.