KL - 47 |
GENERALIn the 1960's, the intelligence community used the KL-47 as an off-line backup for forwarding critical information to national command authorities when a "covered" circuit was unavailable. This was usually due to poor radio frequency propagation causing synchronous crypto gear to lose synchronism.
Worldwide, the key and rotor combinations changed at 0000Z daily (HJ). A rotor basket, set up in advance, was quickly installed at changeover time to preclude any delays in decrypting critical intelligence. Several baskets containing different rotor sets and settings were kept close at hand in the event that a late arriving message used a key from the previous day.
This is the Navy version of the KL-47 which was designated as TSEC/KLB-47. (Photo courtesy NSA/National Cryptologic Museum) |