10 - Secure Media Streaming and Secure Transcoding

Abstract

This chapter describes secure scalable streaming (SSS) and secure transcoding, where co-designing the scalable coding, encryption, and packetization operations enable streaming and mid-network transcoding to be performed without requiring decryption. The chapter highlights that media-aware protection can be used to achieve end-to-end security, flexible mid-network handling, and processing of the protected content. It examines three basic problems: (1) secure streaming from a sender to receiver, (2) secure transcoding at an untrustworthy node in the middle of the network, and (3) secure adaptive streaming of pre-stored content at an untrustworthy sender. The scalable data dependencies are matched up with the encryption dependencies in a manner that allows the resulting secure scalable data to be transcoded by truncating or discarding packets. It adds unencrypted header information to the secure scalable data that can convey the rate-distortion (R-D) information of the various segments of the protected data. A mid-network entity can use this information to perform R-D optimized streaming and transcoding of the protected data without unprotecting the content. The chapter explains this approach's application to non-scalable coders It also explains these approaches' usage in secure media systems, and discusses basic design principles for these systems. It describes the JPSEC standard, which is the first standard that supports SSS and secure transcoding. The chapter concludes by describing that the SSS framework can be extended to create standards for securing other types of media data, including speech, audio, video, and graphics. In regard to the security of the SSS framework, the design of SSS systems use existing, highly studied cryptographic primitives, such as advanced encryption standard (AES) for encryption or hash message authentication code (HMAC) with secure hash algorithm-1 (SHA-1) for authentication.