针对空间链路低带宽和高误码率下的数据安全问题,提出了一种基于有向图构造的卫星遥感图像认证算法.该算法利用率失真理论建立认证优化模型,通过构造有向图获得认证代价和丢包鲁棒性之间的优化权衡.首先,通过分析遥感图像数据压缩码流的结构和位平面编码特点,设计了一种保持码流语法结构的分层分包策略.然后在此基础上,分析了不同层数据包的质量权重和编解码依赖关系,进而采用散列链和散列树相结合的方式来构造最优的认证图,从而实现对图像数据的非平等认证保护.最后,对认证算法的代价、丢包鲁棒性进行了比较分析及仿真实验,并进行了安全性分析.实验结果表明,在不同码率下该算法较其它算法具有更高的峰值信噪比(Peak Signal-to-Noise Ratio,PSNR),即在相同代价情况下该算法较其它算法具有更强的丢包鲁棒性.An authentication method for satellite remote sensing image based on constructing directed graph is proposed in this paper for the low data transmission rate and high bit-error rate on space link. The rate-distortion theory is used to establish an authentication optimization model, our method can obtain the optimal trade-off between the authentication overhead and the packet-loss robustness via constructing the directed graph. Firstly, based on the structure of remote sensing image data compression codestream and the characteristics of the bit-plane coding, a hierarchical packetization strategy is designed to maintain the syntactic structure of original codestream. Secondly, the quality weight of packets and the codec dependencies are analyzed, and hash chain and hash tree are employed to construct the optimal authentication graph for unequal authentication protection. Finally, in terms of computation cost, communication cost, robustness to packet loss, the proposed algorithm is analyzed theoretically and compared with existing algorithms and the security of the proposed algorithm is also analyzed. Experimental results show that the algorithm has higher peak signal-to-noise ratio (PSNR) than other schemes at any bit-rate. Therefore, the proposed scheme has stronger robustness to packet loss
