Card sharing

Card sharing is a method by which independent receivers obtain simultaneous access to a pay television network, using one legitimate conditional access subscription card. Typically, the legitimate card is attached to a personal computer or Dreambox which is connected to the Internet, and is configured to provide the legitimately decrypted control word to other receivers who request the information. This decrypted control word is then used to decode an encrypted conditional access service, as though each other receiver were using its own subscription card. As technology has made the security of smartcards in conditional access systems increase, card sharing has become a more popular method of pirate decryption. Much of the development of card sharing hardware and software has taken place in Europe where national boundaries mean that home users are able to receive satellite television signals from many countries but are unable to legally subscribe to them due to licensing restrictions on broadcasters.

Because the length of the control word is so small (often 16 bytes), delivery of the control words over wide area networks to many different set top boxes is easily possible on a home internet connection. This has sparked off the creation of sharing network groups, in which users can access the group by sharing their subscription cards with the group, and in turn, being capable of receiving the channels which all users' cards can decrypt, as though the user owned every single subscription card. Other networks have also been created, whereby one server has multiple legitimate subscription cards connected to it. Access to this server is then restricted to those who pay the server's owner their own subscription fee.

Another use for card sharing has become apparent as Europe migrates from analog to digital TV. As the tv signal turns digital, a digital set top box is needed for each TV in the household. Each set top box normally needs to have its own smart card in order to be able to decrypt premium channels.Most pay-tv providers (but not all) offer extra subscription cards to subscribers for a reduced fee compared to the original first card. The extra cards usually come with more restrictions than the first card, such as certain channels excluded from being decrypted by any card except the (more expensive) first one. This practice is mostly dictated by the content providers (tv networks) and poses a problem from a consumer rights perspective, as the subscribers are essentially forced to paying for the same channels twice, whereas in the analog world the channels would be unlocked on every TV in the household with only one fee.

In order to avoid paying for the same content twice, many subscribers use card sharing to share their single smartcard among all the receivers in their households, arguing that it is just fair use. This practice can in some cases mean a breach of the contract between the subscriber and the content provider. It is however not an illegal activity, since the subscriber pays for the smartcard and the smartcard is only used within the subscriber's own household.

Card sharing has caused major concern to the conditional access subscription card manufacturers, and their respective pay-tv companies, since virtually every encryption system can be shared, allowing unauthorised access. Unlike the hacking of smart cards, card sharing is relatively new, thanks to the recent increase in home internet speeds. Conditional access providers therefore have few counter measures to combat its use. One such method, used by several providers, is to greatly increase the frequency of changing the control word, used to decode the channel. With changing occurring as frequently as once every 5 seconds, this puts extra stress onto the subscription cards processor, meaning that clients are frustrated by short, but frequent, missed viewing, making viewing possible, but with extreme inconvenience. In response to this, card sharing servers have appeared that caches control words in order to prevent overloading of the smartcards processor if the same code word is requested more than once.

The future of card sharing is unknown, because it is equally unclear how widespread its use is. Many conditional access providers may see it unworthy to produce new cards to send to all subscribers, as their manufacturing costs are too high. Most probably also realize that and the additional "security" will eventually be circumvented anyway. The latest Irdeto cards for example, have been produced in a way by which card sharing seemed not possible, but now they can be shared again.