In 1991 GEC-Marconi Secure Systems claimed to have been in existence under various names for some 40 years. The company had their head office in Liverpool and other sites at Portsmouth and in Quebec Canada.
The increasing growth in Information Technology and the creation of data networks throughout government, commerce and industry brought with it the problem of protecting sensitive information. GEC-Marconi Secure Systems business was the security aspect of network management
An example of their activity was in the late eighties, the Home Office called for competitive trials to be undertaken to research a variety of speech scrambler systems. This was then developed by GEC-Marconi Secure Systems into the Marconi Advanced Scrambler (MASC) system. The Home Office selected MASC as the only recommended speech scrambler for UK police forces. A more recent example was a VLF communication system for submarines.