Objective This document is the IIF Default Scrambling Algorithm (IDSA) Interoperability Specification that is designed to meet the following objectives: ? The specification focuses on IPTV Interoperability issues only. ? The specification assumes that the DRM system is a black box. ? The specification describes a default scrambling/de-scrambling algorithm. ? The specification also describes the signaling for the selection and use of alternative scrambling algorithms. ? This specification only addresses scrambling of MPEG-2 Transport Streams. There are expected to be additional scrambling profiles for use with other transports of IPTV content as these are defined by ATIS IIF. Specifications for any additional scrambling profiles will be given in future revisions of this document.