Study On Security Of Conditional Access System

Digital television, high-definition television and the development of network technology makes a wide application of digital video communications. As its important part, the Conditional Access System (Conditional Access system) is necessary to achieve video information services. This paper describes the basic principles of Digital television conditional access system, analyze the safety of current conditional access system. According to system architecture and encryption system, this paper analyze the defectc about CW, ECM, EMM and the smart card. As attacks to CW, the paper designs a CW Generator of higher safety to generate long-peroid and low-correlation CW.For Attacks to encryption algorithm, this paper analyses the security of DES and RSA; and designs an improved RSA encryption algorithm to resist low-exponential attack and resend attack. For attacks to ECM, EMM and smart card, the paper analyses the probable attack pattern and proposes set-card separation to defense these attacks.