Discret 11, the French TV encryption of the 80s
Summary
The article presents a historical technical account of Discret 11, Canal+'s pay-TV encryption from 1984. It explains how an 11-bit Linear Feedback Shift Register based key is used to line-delay lines in an SECAM signal, the decodeur device used by subscribers, and the anti-cheating scheme with multi-level keys. It also covers piracy, legal barriers, and the system's ultimate retirement and impact on European pay-TV.