A collusion-resistant conditional access system for flexible-pay-per-channel pay-TV broadcasting

• Main Authors: WAN, Zhiguo, LIU, June, ZHANG, Rui, DENG, Robert H.
• Format: text
• Language: English
• Published: Institutional Knowledge at Singapore Management University 2013
• Subjects: Information Security
• Online Access: https://ink.library.smu.edu.sg/sis_research/1638; https://ink.library.smu.edu.sg/context/sis_research/article/2637/viewcontent/A_collusion_resistant_conditional_access_system_for_flexible_pay_per_channel_pay_TV_broadcasting.pdf
• Institution: Singapore Management University

Pay-TV Broadcasting system, an extensively de- ployed application, charges its subscribers when receiving the broadcasted video. A conditional access system (CAS) ensures security for the Pay-TV broadcasting system, which is designed to control TV channel/program access to only authorized subscribers. There are mainly three CAS models: pay-per-channel (PPC), pay-per-view (PPV), and flexible-pay-per-channel (F- PPC). F-PPC is a novel model which combines the properties and advantages of both PPC and PPV. Several key management schemes with four-level hierarchical key structure have been proposed for this model. In this paper, we point out a severe security weakness of these schemes against collusion attacks and propose a new CAS scheme with three-level hierarchical key structure using ciphertext-policy attribute-set-based encryp- tion. Our scheme provides scalable, flexible, fine-grained, and most importantly, collusion-resistant access control for Pay-TV broadcasting applications. The proposed scheme is designed to support all operations in Pay-TV applications. We then provide a detailed analysis on security, performance and computation complexity of our scheme. We also implement the scheme and show that it is both efficient and flexible for F-PPC CAS for Pay-TV broadcasting applications.