Sufficient Encryption with Codewords and Bin-strings of H.264/SVC

Multi-layered scalable bit-stream distribution requires protection for the rendering and transmission of its individual layers. This paper presents a sufficient encryption (SE) scheme for SVC layers which maintains the compression efficiency and the format compliancy of scalable bit-streams, without compromising the security. The purpose of SE is achieved by applying the partial encryption on carefully selected codewords and bin-strings of the CAVLC and CABAC of H.264/SVC respectively. The performance of the scheme is tested on various resolution sequences, which demonstrate the advantages of the scheme when compared to alternative techniques. These advantages include: minimal computational delay by encrypting partial data; no bit-rate escalation by keeping the compression ratio unchanged; and, format compliancy of the bit-stream at the decoder. A comparative security analysis of the scheme confirms that it is suitable for commercial, real-time applications. The minimal increase in processing requirements ensures that the scheme is highly suitable for video distribution to users who have subscribed to differing video qualities on end systems ranging from small handheld devices to those with high computational capability.