Analog Video Scrambling help (circuit or design)

[thanhhavdt]

I have a need for a circuit or design for a video scrambling system. I need to scramble analog cameras between a 750 foot cable runs. I prefer a design or real schematic so I can also see how its done and build it myself. Preferred is cut and rotate type I would consider costs for IP core required for a DSP design. but anything good would be useful.
Any help appreciated

Thanks in advance