Combined Cipher Machine
The Combined Cipher Machine (CCM) (or Combined Cypher Machine) was a common cipher machine system for securing Allied communications during World War II and, for a few years after, by NATO. The British Typex machine and the US ECM Mark II were both modified so that they were interoperable. == History == The British had shown their main cipher machine — Typex — to the US on their entry into the war, but the Americans were reluctant to share their machine, the ECM Mark II. There was a need for secure inter-Allied communications, and so a joint cipher machine adapted from both countries' systems was developed by the US Navy.