Patent ID: 8548168

Claim:
A security module for use in securing an encrypted signal, the security module comprising: a signal interface for receiving the encrypted signal; a host interface that is coupleable to a host; a memory module; a processing module, coupled to the signal interface, the host interface and the memory module, the processing module operable to: receive encrypted decryption code from the host via the host interface; decrypt the encrypted decryption code to form decrypted decryption code that is operable to decrypt the encrypted signal; send the decrypted decryption code to the host via the host interface; transfer the encrypted signal to the host via the host interface; monitor the security of the decrypted decryption code via security signaling generated by the host in response to the host's decryption of the encrypted signal and sent to the security module via the host interface during the transfer of the encrypted signal to the host to detect potential tampering with the decrypted decryption code wherein the security signaling includes sending hashing code input data to the host at intervals and wherein the monitoring of the security of the decrypted decryption code includes receiving updated hashing code output data from the host, comparing the received updated hashing code output data to an expected updated hashing code output data and detecting potential tampering when the received updated hashing code output data compares unfavorably to the expected updated hashing code output data; and discontinue transfer of the encrypted signal when the security signaling indicates the potential tampering with the decrypted decryption code.