In the technological era, the primary source of information is in the form of digital data, which has to be secured while storing or transmitting during communication over an unsecured network. Different approaches are used to provide security to digital data, viz. text, audio, image, and video. This paper initially explains the security system such as cryptography, watermarking, and steganography and their comparative analysis based on different characteristics, viz. satisfaction level of objective, type of carrier object and secret information to be used, dependency of security level, and quality assessment parameters. This review article focuses more on steganography methods applied over video. The various methods implemented for video steganography in compressed domain, viz. inter-frame and intra-frame prediction, motion vector estimation, entropy coding (CAVLC and CABAC), and transformed and quantized coefficients of DCT, DST, and DWT, etc. and the methods based on spatial and transform domain for uncompressed video are briefly described. It is followed by the detailed analysis of related work done by various researchers in video steganography and the obtained experimental results. Furthermore, the confidential data hiding in compressed videos are explained using Moving Picture Expert Group (MPEG—1, MPEG—2, MPEG—4), Advanced Video Coding (AVC)/H.264, and High-Efficiency Video Coding (HEVC)/H.265 that includes both spatial and transform domain. This paper summarizes and explains the detailed investigations of numerous techniques of video steganography based on the comprehensive literature survey. The methods used to assess the performance of video steganography are analyzed based on the quality assessment parameters such as imperceptibility; measured by peak signal to noise ratio (PSNR), mean square error (MSE), and structural similarity (SSIM), robustness; measured by bit error rate (BER) and similarity (Sim), and embedding capacity; measured by hiding ratio. The overall review of past literature facilitates to have in-depth knowledge for upgrading the video steganography.

在技​​术时代，信息的主要来源是以数字数据的形式，在通过不安全的网络进行通信期间进行存储或传输时，必须对其进行保护。使用不同的方法为数字数据提供安全性。文字，音频，图像和视频。本文首先解释了安全系统，例如密码术，水印和隐写术，并根据不同的特征对它们进行了比较分析。目标的满意度，所使用的载体对象和秘密信息的类型，安全级别的依赖性以及质量评估参数。这篇评论文章重点介绍了应用于视频的隐写术方法。在压缩域中为视频隐写术实现的各种方法，即。帧间和帧内预测，​​运动矢量估计，简要介绍了熵编码（CAVLC和CABAC）以及DCT，DST和DWT等的变换和量化系数，以及基于空间和变换域的未压缩视频的方法。接下来是对视频隐写术中各个研究人员所做的相关工作的详细分析以及所获得的实验结果。此外，使用运动图像专家组（MPEG-1，MPEG-2，MPEG-4），高级视频编码（AVC）/H.264和高效视频编码（HEVC）来解释隐藏在压缩视频中的机密数据。 /H.265，包括空间域和变换域。本文在综合文献综述的基础上，总结并解释了许多视频隐写技术的详细研究。基于质量评估参数（如不可感知性），分析了用于评估视频隐写术性能的方法。通过峰值信噪比（PSNR），均方误差（MSE）和结构相似度（SSIM），鲁棒性进行测量；通过误码率（BER）和相似度（Sim）以及嵌入容量进行测量；用遮盖率测量。对过去文献的全面回顾有助于获得有关升级视频隐写术的深入知识。