Patent ID: 8583930

Claim:
A method of security authentication between a secure micro (SM) and a transport processor (TP) in a downloadable conditional access system (DCAS), the method comprising: receiving, at the SM, a validation verification message which includes an encryption seed key for an identifier pair consisting of a secure micro (SM) identifier and a transport processor (TP) identifier; and generating, at the SM, a content key encryption key (CKEK) and a hashed message authentication code key (HMAC_KEY) based on the encryption seed key, and encrypting data to be transmitted to the TP through the CKEK and the HMAC_KEY authentication between the SM and the TP using the encryption seed key, wherein the encrypting of the data to be transmitted to the TP includes generating the CKEK and the HMAC_KEY and transmitting a message including the encryption seed key to the TP, receiving a CKEK and an HMAC_KEY which are generated by the TP using the encryption seed key, and comparing the received CKEK and the HMAC_KEY, respectively, with the CKEK and the HMAC_KEY of the SM, encrypting the data to be transmitted to the TP and performing hashed message authentication on a message to be transmitted to the TP if the CKEKs and the HMAC_KEYs are identical, respectively, to each other.