The CSA 3 descrambler IP core is hardware implementation of DVB Common Scrambling Algorithm version 3. It was designed to remove protection from scrambled broadcast data by flow-through decryption of transport stream. It has simple custom interface for data with flow control and APB 3.0 slave interface (backward compatible with APB 2.0) for set keys.
The CSA 3 descrambler IP core was designed for handled up to four different transport streams with even and odd keys for each TS. Handling of one 128-bit data word takes about 78 clock cycles (i.e. about 5 clock cycles per 1 byte).