The History of Traffic Analysis – WWI – Vietnam Part 8 of 8

The Cold War – The Early Stages

On Friday October 29, 1948 (known by cryptologists as Black Friday), the Soviets executed a massive change of their code and cipher systems and communications procedures with devastating effect upon the U.S. efforts to produce COMINT.

“Out of this devastation, Russian plaintext communications emerged as the principal source of intelligence on our primary Cold War adversary.”(42) Outside of plaintext, one of the only other sources of information was T/A.(43) That was the environment within which traffic analysts worked during the Cold War. With cryptanalysis being in a posture much reduced from the days of Enigma during WWII, T/A and plain language texts gained a more prominent role.