一种基于国密算法的音视频选择性加密方案

A Selective Encryption Scheme for Audio and Video Based on the National Cryptographic Algorithm

针对目前以国密算法为基础的音视频数据加密方案不完善、加密效率与安全性难以权衡的问题,文章在腾讯实时音视频(Tencent Real-Time Communication,TRTC)架构下设计了一种基于国密算法的音视频选择性加密方案。根据音视频应用的特点与需求提出口令认证与协同签名相结合的身份认证方案,通过分析SM4算法与H.264编码方式的特点,使用SM4-CFB模式对编码后帧内关键语法元素IPM、MVD和RC进行加密,实现了高效的音视频数据选择性加密。实验证明,该方案有效降低了加密数据量,提高了加密速度,并且具有较高的密码安全性和感知安全性。

Aiming to address the current issues of imperfect encryption schemes based on national cryptographic algorithm in audio and video data,balancing encryption efficiency and security,this paper designed a selective audio-video encryption scheme within the TRTC audio-video architecture,based on national cryptographic algorithms.The scheme proposed an identity authentication mechanism combining password authentication and collaborative signature,tailored to the characteristics and requirements of audio-video applications.By analyzing the features of the SM4 algorithm and H.264 encoding method,the scheme employed SM4-CFB mode to encrypt key syntax elements such as IPM,MVD,and residual coefficients within encoded frames,achieving efficient selective encryption of audio-video data.Experimental results demonstrate that this approach effectively reduces encrypted data volume,enhances encryption speed,and maintains high levels of cryptographic security and perceptual security.