Rockex

Rockex, or Telekrypton, was an offline one-time tape cipher machine known to have been used by Britain and Canada from 1943. It was developed by Benjamin deForest Bayly, working during the war for British Security Coordination.

"Rockex" was named after the Rockefeller Center, together with the tradition for naming British cipher equipment with the suffix "-ex" (e.g. Typex).