基于使用轻量级流算法的DCT系数变换多媒体内容加密

针对实时安全系统中多媒体内容加密时由于数据量较大而导致计算开销非常大的问题,为了综合考虑安全性及实时性,提出了基于使用轻量级流算法的DCT余弦转换多媒体内容加密算法。首先提出了一种轻量、快速的加密算法,通过将明文划分成不同部分并且使用流加密算法对信息的每个部分分别进行加密；然后,基于设计部分加密方案的三项基本原则和对抗部分加密攻击,提出了两种DCT变换系数的部分加密方案；最后,通过对峰值信噪比、针对部分加密攻击的安全性、性能的分析评估了所提算法的有效性及可靠性。分析结果表明,相比A5/1和W7两种较为先进的流密码算法及另外两种加密模式(DC系数加密和无变换加密),提出的流加密算法和两种DCT加密方案更加适用于要求高速计算和足够安全的多媒体实时安全系统。

Transform Coefficients Based on Lightweight Stream Algorithm for Encryption of Multimedia Content

For the issue that it has big data in encryption of multimedia content which will cause large computational overhead in real-time security system, DCT transform coefficients based on lightweight stream algorithm is proposed to weigh the security and real time. Firstly, a lightweight, fast encryption algorithm which using stream encryption algorithm to encrypt each part of information after dividing content into different parts. Then, two DCT transform coefficients partial encryption schemas are proposed based on three baseline criterion of designing partial encryption schemas and attacks for which. Finally, the effectiveness and reliability of proposed algorithm is verified by analyzing peak signal to noise ratio, security of partial encryption attack and performance. Analysis results show that proposed stream encryption algorithm and the two DCT schemas are more suitable for the real-time security system relying on high-speed computing and insufficient safety than advanced stream encryption algorithms A5/1, W7 and two other encryption patterns (encryption with DC coefficients and encryption without transform).