This image was acquired from
wikimedia. It was marked as Public Domain or CC0 and is free to use. To verify, go to the source and check the information there.
Keywords from Image Description:
Fourrotorenigma. four rotor Enigma machine vectorsite net html Web page vectorsite net Image Greg Goebel Public Domain as stated in vectorsite net This site contains set of publicdomain writings on range of subjects All documents have been written by myself and are free for use in the public domain many of the illustrations