Editing Common Scrambling Algorithm (section)

=== Stream cipher ===

The first 32 round of the stream cipher are used for initialization and do not generate any output.
The first 64 bits of data are used as [[initialization vector]] during this phase and are left unchanged.
The stream cipher then generates 2 bits of pseudo-random stream on each round which are xored starting at bit 64 of the packet.

[[File:Dvbcsa stream.svg|800px|border|Stream cipher details]]