Piracy protection for streaming content in home networks

Abstract

In this paper we study content protection techniques to defend against piracy for streaming content in home networks where multiple digital devices are connected into a peer-based cluster and seamlessly work together. We are particularly interested in the anonymous re-broadcasting attack where pirates re-distribute the per-content encrypting key or the decrypted plain content. In literature, to defend against an anonymous attack, content is usually built with different variations. For example, content is divided into multiple segments, each segment comes with multiple variations (e.g., watermarks), and each variation is differently encrypted. Each device only has the key to decrypt and play back one variation per segment through the content. The re-distributed keys can be linked back and used to identify the original devices (terms as traitors) who were given those keys and involved in the piracy. This technology works well for prerecorded content scenarios in which a trusted party outside the device pool can deliberately author the content with multiple variations. However it cannot be applied to a peer-based home network when the streaming content is brought into the home network via a peer device who is not a special trust party and who is not allowed to know the secret keys of other peer devices. On the other hand, the trend of the consumer appetite for digital content is increasingly switching from physical media to streaming and internet consumption. In this paper we have designed the first content protection system that allows a recording device inside the home network to bring the streaming content into the home network in a secure way that devices and only devices in the same home network can playback the recording. More importantly, the recorded content without variations can still be used to obtain forensic information, when anonymous piracy attacks occurs, to identify the source devices that participated in the piracy attack. The identified traitorous devices can be revoked for future content access. The technology described in this paper is used to enable the secure sharing of premium quality High Definition content across a consumer's all audio-video devices at its home networks. © 2011 IFIP International Federation for Information Processing.