VideoCrypt

Introduction

There were several proposed or utilised methods of viewing content without a valid card at the time of broadcast. These were not as convenient as realtime decoding but would still enable the viewing of premium content such as movies, sporting events, or pay-per-view, albeit at a later time when access to the relevant keys or cards could be acquired.

How It Worked

The first proposal was that a decoder without a card could have its card reader connected to a decoder which does have a valid card. In theory this could be duplicated as many times in a chain as there are boxes required, however there are some practical limitations such as distance. The data could be distributed via online communication systems, a stream of data relayed via IRC perhaps, but this requires that each person wishing to view a channel have a suitable internet-connected computer, with modem, with an ongoing telephone call through which to connect, and have it connected to the decoder. This is viable and effectively realtime but not necessarily practical for most viewers, it could also be expensive as it requires a constant connection to the internet which, at the time, was often billed per minute rather than the more modern approach of per data unit used. It would also require an dialup modem and connection capable of exceeding the data transfer rate of the viewing card’s chip.

Another take on this approach is to simply record the channel to be viewed onto videotape and share both it and a valid viewing card. This would enable anybody in possession of both items to view the content. This could also be achieved by recording the output of the decoder, provided there were no preventative measures such as Macrovision, or the VCR was capable of ignoring them.

For those unable to exchange tapes and cards, “Delayed Data Transfer” would be a suitable replacement. This involves a similar recording of the content to the tape/card combination, however the physical viewing card could be replaced with a record of the data stream from a valid card during the viewing of that programme. For example, a scrambled recording could be made of a movie from Sky Movies, the hopeful viewer would visit an appropriate source of dump files (VCL files), download the VCL file applicable to that channel during the time corresponding to the duration of the movie, replay the video tape through a decoder, and stream the contents of the VCL file to the decode through the card slot as though it were a real card hours in the past.

Pay-per-view activation codes were also shared via communication systems such as BBSs, evidently the data sent to the card upon activation/granting of credit to enable viewing of the events was captured and relayed to those who wished to use it. This data was then injected into viewing cards using Phoenix tools (usually used to reactivate inactive cards). This would, provided the viewer were to obtain the codes quickly enough, enable realtime viewing of such an event.

Mitigation