The KG-13 was
a cipher device used by the United States during the Cold War period. The Crypto museum
page says:
‘KG-13 was a universal digital
fully-transistorised full-duplex key generator, developed in the USA around
1963. It was intended for the encryption and decryption of external generated
data, such as digitised voice and facsimile data.’
In the same
page there is information pointing to its possible exploitation by the Soviet
Union:
‘Between October 1982 and January 1983,
whilst working at the US Air Force, electronics engineer James Atkinson
discovered a series of serious flaws in the KOKEN stages of the KG-13's
internal pseudo random stream generator [4].
Atkinson had been memorizing all current and historical circuit diagrams of the
KG-13, the KY-3 and all of their FLYBALL modules, as a mental exercise. When
going over the circuit diagram in his mind, he began to doubt its mathematical
strength.
More than 20 years after the introduction of the KG-13, he was able to prove
that most of the KOKEN stages were mathematically flawed, rendering the system compromised, and possibly leaking highly classified information
to the Russians.’
KG-13 Encryption Sabotage Detection
October 1982 – January 1983
Complete memorization of all current
and historical schematics and timing and logic charts of KG-13 and KY-3
encryption system.
Examining the schematics of the
ciphers, key cards, as a mental memorization exercise, and then identified
suspected flaws with the mathematic engines inside the equipment actually
deployed.
Actually determined that most of the modules or "Koken stages" in the
KG-13 were mathematically "flawed", and rendered compromised.
The cryptographic flaw enabled an eavesdropper to exploit all Top Secret data
flowing thorough the "crown jewel systems" of U.S. Encryption called
the KG-13.
An immediately and emergency modification to the circuits of the Koken stages
resolved this matter, but not after it have been in place for over 20 years,
and we had been leaking classified intelligence to the Russians.
The NSA was highly embarrassed at somebody finding this screw up merely by
studying the schematics and logic tables, and finding what the NSA did not see
for decades.
The end result was tens of million of dollars being spend to seal the breach.
I ended up being a rock-star of sorts within the technical counterintelligence
circles.