Basic Interoperable Scrambling System

Basic Interoperable Scrambling System, usually known as BISS, is a satellite signal scrambling system developed by the European Broadcasting Union, Eurovision Media Services and a consortium of hardware manufacturers.

Unencrypted satellite feeds allowed anyone with the correct equipment to view the program material.

Proprietary encryption methods were determined by encoder manufacturers, and placed major compatibility limitations on the type of satellite receiver (IRD) that could be used for each feed.

BISS was an attempt to create an "open platform" encryption system, which could be used across a range of manufacturers equipment.

There are mainly two different types of BISS encryption used: Only a decoder with the correct secret BISS-key will be able to decrypt a BISS-E feed.