A Video Steganography for H.265/HEVC Based on Multiple CU Size and Block Structure Distortion

2026-03-24

AI Summary

This work proposes a novel steganographic algorithm for H.265/HEVC that addresses the vulnerability of existing coding unit (CU)-based methods, which often disrupt the original CU structure and thus exhibit insufficient resistance to steganalysis. By designing multi-scale CU mapping rules and a three-level block structural distortion function, the method embeds secret information into motion-compensated residual regions in the compressed domain while minimizing perturbations to the original CU partitioning. A key innovation is the introduction of a Coding Unit Block Structure Stability Metric (CBSSM), which jointly optimizes embedding locations and distortion costs. Experimental results demonstrate that the proposed approach significantly enhances resistance to steganalysis while simultaneously improving visual quality, suppressing bitrate increase, and achieving higher embedding capacity.

Technology Category

• Computer Vision: Adversarial Attacks & Robustness
• Reasoning under Uncertainty: Stochastic Optimization
• Search and Optimization: Heuristic Search

Application Category

• Graph Algorithms and Modeling for the Web: Graph embeddings and representation learning for Web-related graphs
• Security and Privacy: Large-scale security measurements
• Web Mining and Content Analysis: Robustness and generalizability of Web mining methods

Abstract

Video steganography based on block structure, which embeds secret information by modifying Coding Unit (CU) block structure of I-frames, is currently a research hotspot. However, the existing algorithms still suffer from the limitation of poor anti-steganalysis, which results from significantly disrupting the original CU block structure after embedding secret information. To overcome this limitation, this paper proposes a video steganography algorithm based on multiple CU size and block structure distortion. Our algorithm introduces three key innovations: 1) a CU Block Structure Stability Metric (CBSSM) based on CU block structure restoration phenomenon to reveal the reasons for the insufficient anti-steganalysis performance of current algorithms. 2) a novel mapping rule based on multiple CU size to reduce block structure change and enhance embedding capacity. 3) a three-level distortion function based on block structure to better guide the secret information embedding. This triple strategy ensures that the secret information embedding minimizes disruption to the original CU block structure while concealing it primarily in areas where block structure changes occur after recompression, ultimately enhancing the algorithm's anti-steganalysis. Comprehensive experimental results highlight the crucial role of the proposed CBSSM in evaluating anti-steganalysis performance even at a low embedding rate. Meanwhile, compared to State-of-the-Art video steganography algorithms based on block structure, our proposed steganography algorithm exhibits greater anti-steganalysis, as well as further improving visual quality, bitrate increase ratio and embedding capacity.

Problem

• video steganography
• H.265/HEVC
• block structure distortion
• anti-steganalysis
• coding unit

Innovation

• Video Steganography
• H.265/HEVC
• CU Block Structure
• Anti-Steganalysis
• Distortion Function