A method and apparatus for an iterative cryptographic block under the
control of a CPU and without a fixed number of stages. In one embodiment,
a first cryptographic block descrambles received information using an
internal key or a preprogrammed key to form a descrambled key or
descrambled data. A data feedback path stores the descrambled data as
internal data and provides the internal data or the external data as data
input to the first cryptographic block. A key feedback path stores the
descrambled key as an internal key and provides the internal key or the
preprogrammed key to a key input of the first cryptographic block. A
second cryptographic block descrambles received content using a final
descrambling key. Other embodiments are described and claimed.