Method and apparatus for securing control words

According to one embodiment, a method of descrambling digital multimedia content starts by sending an out-of-band request for encrypted control data to a headend. A descrambler integrated circuit may then receive digital program data in a scrambled, format and the encrypted control data. The encrypted control data may then be decrypted entirely within the descrambler integrated circuit using a multiple-step decryption process starting with a unique key permanently stored in the descrambler integrate circuit and using the partial decryption of control data from the previous decryption step to generate a key to decrypt subsequent encrypted control data. The scrambled digital program data may then be descrambled in the descrambler integrated circuit using the decrypted control data from the last decryption step. Other embodiments are described.