Chung Yongwha, Lee Sungju, Jeon Taewoong, Park Daihee
Department of Computer Information Science, Korea University, Sejong KS002, Korea.
Sensors (Basel). 2015 Apr 2;15(4):7953-68. doi: 10.3390/s150407953.
In transmitting video data securely over Video Sensor Networks (VSNs), since mobile handheld devices have limited resources in terms of processor clock speed and battery size, it is necessary to develop an efficient method to encrypt video data to meet the increasing demand for secure connections. Selective encryption methods can reduce the amount of computation needed while satisfying high-level security requirements. This is achieved by selecting an important part of the video data and encrypting it. In this paper, to ensure format compliance and security, we propose a special encryption method for H.264, which encrypts only the DC/ACs of I-macroblocks and the motion vectors of P-macroblocks. In particular, the proposed new selective encryption method exploits the error propagation property in an H.264 decoder and improves the collective performance by analyzing the tradeoff between the visual security level and the processing speed compared to typical selective encryption methods (i.e., I-frame, P-frame encryption, and combined I-/P-frame encryption). Experimental results show that the proposed method can significantly reduce the encryption workload without any significant degradation of visual security.
在通过视频传感器网络（VSN）安全传输视频数据时，由于移动手持设备在处理器时钟速度和电池容量方面资源有限，因此有必要开发一种高效的方法来加密视频数据，以满足对安全连接日益增长的需求。选择性加密方法可以在满足高级安全要求的同时减少所需的计算量。这是通过选择视频数据的重要部分并对其进行加密来实现的。在本文中，为确保格式合规性和安全性，我们提出了一种针对H.264的特殊加密方法，该方法仅对I宏块的直流/交流系数和P宏块的运动矢量进行加密。特别是，所提出的新选择性加密方法利用了H.264解码器中的错误传播特性，并通过分析与典型选择性加密方法（即I帧、P帧加密和组合I/P帧加密）相比视觉安全级别和处理速度之间的权衡来提高整体性能。实验结果表明，所提出的方法可以显著减少加密工作量，而不会对视觉安全性造成任何显著下降。
