| 摘要 |
<p>In a downloadable conditional access system (DCAS), preferably all DCAS-specific code is implemented in a configurable secure (CS) processor that is in communication with the host processor. Preferably, no DCAS-specific code is executed in the host processor. The host processor delivers commands to the CS processor, which the CS processor performs to configure itself in accordance with the particular DCAS encryption scheme used by the DCAS. Once configured, the CS processor executes a DCAS software module that has been downloaded to the CS processor, which looks for the corresponding EMMs and ECMs, processes them to obtain the CW, and then uses the CW to decrypt the content stream.</p> |
