DVB CSA has flaw

The Farncombe Technology consultancy has called for a replacement for the DVB Common Scrambling Algorithm (CSA), arguing that the growing ubiquity of residential always-on fast internet access has exposed a flaw in the system.
It says the practice of detecting and sharing control words as they are passed to the CSA is at a point where the pay-TV business is beginning to face the same illegal downloading practices that have undermined the music sector. The company believes the presence of the hardware-based system is also distorting the market, adding to the cost of in-home distribution.
"If just one of an operatorís set-top boxes is hacked in a way that the control words can be extracted then there are websites that can put them up on the internet and everyone with a standard DVB device can see a paid service for nothing," warned Farncombeís founding partner Andrew Glasspool. "If the operatorís scrambling [algorithm] was in some way different then only its own subscribers would be able to receive the control word."
Farncombe acknowledges that there were sound reasons for the introduction of a common algorithm. It underpins the Simulcrypt system used by regulators to promote competition between pay-TV operators. It also lowers the entry-barrier for new CA vendors, and allows operators to swap between different CA systems relatively easily. Farncombe believes that any replacement for the CSA should aim to replicate these benefits.