[mcbridematt]

The BBC ran a service called BBC Select in the early 90s with a VideoCrypt derivative, rather than line cut they shuffled blocks of lines around the screen - which worked better over more lossy and interference prone terrestrial transmissions.

The technical paper from BBC R&D is quite interesting: http://downloads.bbc.co.uk/rd/pubs/reports/1995-11.pdf

There are a couple of captures of the scrambled transmission on Youtube - it's definitely far more advanced than the earlier Canal method https://youtu.be/HcCdw97_ESA