On the 11th of January 1963 the USA and UdSSR finished the Cuba crises with a common agreement. In the same year the "hot line" between Kennedy and Chruschtschow was established for a faster and more secure message transmission in case of a crisis. The encryption in Moscow and Washington was done with the ETCRRM strip-mixer series. This machine used "once- only" punched paper tape as a key stream to encrypt teleprinter tape messages. ETCRRM was designed for low speed start-stop or synchronous applications and especially with a teleprinter as an input or output device.
By the way. Did you know, that Geile Siech in Swiss German means something like Good Lad?