Editing VideoGuard (section)

==Reverse engineering==

VideoGuard is unusual in that legitimate external [[conditional-access module]]s are not available, the encryption system instead being built into the hardware and firmware of platform-supplied set-top boxes. However, several groups have managed to reverse-engineer VideoGuard to the point where a legitimate subscriber's card can be utilised in third-party receivers to decrypt those channels which that subscriber is authorised to view. A software CAM emulator exists for the [[Dreambox]] & [[Triple-Dragon]] [[Linux]]-powered satellite receivers, along with the Diablo, Dragon, Giga-Blue and T-Rex conditional-access modules. Some of the reverse-engineered solutions are unable to update the card, meaning the legitimate card needs to be returned to official Sky receiver for a few hours (or overnight) to be refreshed, or programmes will no longer decrypt. An example of a reverse-engineered solution that does support card updates is NDSCam.<ref>ReadMe.txt from NDSCam ver.0.0.0.7</ref>