精细粒度可扩展编码中基于VOP的基本层加密算法  

VOP Based Base Layer Encryption Algorithm in Fine Granular Scalable Coding

作　　者：文振焜[1] 袁春[2] 张基宏[1] 

机构地区：[1]深圳大学信息工程学院,广东深圳518060 [2]清华大学计算机系,北京100084

出　　处：《电子学报》2008年第8期1547-1551,共5页Acta Electronica Sinica

基　　金：国家自然科学基金(No.60573132);国家自然科学基金(No.60503063);深圳市项目(No.200507)

摘　　要：本文提出的细粒度可扩展编码中基于VOP(video object plane)的基本层加密算法,是利用FGS(fine granu-larity scalable)压缩视频流的分层特点和MPEG4视频对象VO(video object)编码原则,结合改进的C&S(chain and sum)加密算法,通过提取并加密基本层VOP的关键数据,包括形状、纹理、运动和全局背景等,实现FGS整体流的加密.本加密算法使加密数据流无需解密和加密操作就可支持网络节点的变换编码以适应带宽变化.以VOP为单位的加密策略和改进的C&S加密算法的采用,使媒体流丢包、位错等传输错误受到限制,加密后的媒体流没有任何比特增加,加密密钥的相应变化,抵御了已知明文攻击.通过对MPEG提供的三个序列forman、akyio和carphone以采样率为3、处理帧数为300帧的测试,测得C&S,RC4和RC5的处理速度分别约为23.5,64.5和42.7M字节/每秒,加密安全特性和混乱视觉效果十分理想.By using the leveled characteristics of fine granularity scalable （FGS） compressed video, the MPEG4 video object coding rules and the improved C＆S（chain and sum）, the base-level enctyption algorithm, which is based on Video object plane （VOP） in Fine-grain extensible coding ,retrieve and encrypt the key data,including shape,texture,motion and global background, of the base-level VOP to encrypt the FGS steaming. The algorithm supports the transform coding of the network node to adapt to the variation of the bandwidth without any encryption and decryption operations. The use of encryption in VOP unit and C＆S algorithm effectively reduce the media stream package loss and transport errors. There is no size increment in the encrypted data steam and the variation of the encrypted key withstands the Known-plaintext attack.By the experiments on three series forman, akyio and carphone provided by Moving Pictures Experts Group （MPEG） in a sampling rate of 3 of 300 processing frames, the processing speed of C＆S,RC4 and RC5 are 23.5, 64.5 and 42.7M b/s. The results also show a satisfying encrypted security and descrambled visual effect.

关 键 词：FGS 可扩展编码 视频加密 数字权力管理DRM 

分 类 号：TN919[电子电信—通信与信息系统]