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:
SIGRUV encryption disk SIGSALY Speech Encipherment System exhibit National Cryptologic Museum DSC. en Exhibit in the National Cryptologic Museum Fort Meade Maryland USA All items in this museum are unclassified items created by the United States Government are not subject to copyright restrictions own Daderot cczero SIGSALY