高效率影片編碼(H.265/HEVC)為現今常用的影片編碼標準，為了保護影片內容的隱私，許多研究提出了H.265/HEVC影片選擇加密方案。由於近年研究提出的係數加擾方案，其安全性仍不佳，因此在這論文提出了基於混沌映射的係數加擾方案，借助混沌映射的偽隨機性，可以有效擾動係數分佈，以提高係數加擾的隨機性。同時，在H.265/HEVC中，存在一些係數的編碼方式可以有效提高編碼係數的效率，因此也規劃了係數加擾條件，排除這些係數進行係數加擾，使係數加擾操作不影響許多位元率開銷。係數加擾結合語法元素加密，包括動作向量差(MVD)資訊(mvd_sign_flag、abs_mvd_minus2後綴)、量化轉換係數(QTC)資訊(coeff_sign_flag、coeff_abs_level_remaining後綴)與亮度幀內預測模式(Luma IPM)資訊，可以有效破壞影片內容，以確保影片內容的隱私保護。我們所提出的方案與Slice同步，確保丟失一些Slice之後不影響解密影片內容。還有，採用AES-CTR生成的隨機序列與H.265編碼流相關聯，以抵抗選擇明文攻擊。實驗結果表明提出的方案具有高安全性、符合格式兼容、執行時間快速、與Slice同步更新以及抵抗常見攻擊等等特性，並有效改善係數加擾的位元率開銷。因此提出的方案可以為H.265/HEVC影片選擇加密方案提供更棒的選擇。

High efficiency video coding (H.265/HEVC) is a commonly used video coding standard today. To protect the privacy of video content, much research has proposed H.265/HEVC video selective encryption schemes. Since the coefficient scrambling scheme proposed in recent years is still not safe, a coefficient scrambling scheme based on chaotic maps is proposed. With the help of the pseudo-randomness of chaotic maps, the distribution of coefficients can be effectively disturbed to improve the randomness of coefficient scrambling. At the same time, in H.265/HEVC, there are some coefficient coding methods that can effectively improve the efficiency of coding coefficients, so the coefficient scrambling conditions are also planned to exclude these coefficients from coefficient scrambling, so that the coefficient scrambling operation doesn’t affect a lot of bit rate overhead. Coefficient scrambling combined with syntax element encryption, including motion vector difference (MVD) information (mvd_sign_flag, abs_mvd_minus2 suffix), quantized transform coefficient (QTC) information (coeff_sign_flag, coeff_abs_level_remaining suffix) and luma intra prediction mode (Luma IPM) information, can effectively destroy video content to ensure privacy protection. The proposed scheme is synchronized with slices to ensure that the decrypted video content will not be affected after losing some slices. In addition, the random sequence generated by AES-CTR is associated with the H.265 encoded stream to resist chosen plaintext attacks. Experimental results show that the proposed scheme has the characteristics of high security, format compliant, fast execution time, synchronous update with slice, and resistance to common attacks, etc., and effectively improves the bit rate overhead of coefficient scrambling. Therefore, the proposed scheme can provide a better choice for H.265/HEVC video selection encryption scheme.

論文審定書 i
摘要 ii
Abstract iii
目錄 iv
圖目錄 vi
表目錄 viii
第一章 簡介 1
1.1 論文概述 3
1.2 論文目標 3
1.3 論文貢獻 3
1.4 論文架構 4
第二章 背景知識與文獻探討 5
2.1 高效率影片編碼 5
2.1.1 編碼架構 6
2.1.2 樹形編碼單元 7
2.1.3 CABAC 9
2.1.4 網路抽象層單元 10
2.2 影片加密種類 12
2.3 混沌映射 16
第三章 研究方法 18
3.1 隨機序列生成 21
3.2 係數加擾 22
3.3 語法元素加密 27
第四章 實驗結果 34
4.1 主觀視覺分析 35
4.2 客觀指標分析 36
4.3 資訊熵分析 39
4.4 邊緣檢測分析 40
4.5 位元率開銷分析 42
4.6 Slice丟失分析 43
4.7 密鑰空間分析 44
4.8 密鑰敏感性分析 44
4.9 選擇明文攻擊分析 46
4.10 替換攻擊分析 46
4.11 執行時間開銷分析 48
4.12 比較分析 48
第五章 結論 51
參考文獻 52

[1] F. Hartung and M. Kutter, "Multimedia Watermarking Techniques," Proceedings of the IEEE, vol. 87, no. 7, pp. 1079-1107 , 1999

[2] M.D. Swanson, M. Kobayashi, and A.H. Tewfik, "Multimedia Data-Embedding and Watermarking Technologies," Proceedings of the IEEE, vol. 86, no. 6, pp. 1064-1087, 1998

[3] T. Wiegand, G. J. Sullivan, G. Bjontegaard, and A. Luthra, "Overview of the H.264/AVC Video Coding Standard," IEEE Transactions on Circuits and Systems for Video Technology, vol. 13, no. 7, pp. 560-576, 2003

[4] G. J. Sullivan, J-R Ohm, W-J Han, and T. Wiegand, "Overview of the High Efficiency Video Coding (HEVC) Standard," IEEE Transactions on Circuits and Systems for Video Technology, vol. 22, no. 12, pp. 1649-1668, 2012

[5] G. V. Wallendael, J. D. Cock, S. V. Leuven, A. Boho, P. Lambert, B. Preneel, and R. V. d. Walle, "Format-Compliant Encryption Techniques for High Efficiency Video Coding," IEEE International Conference on Image Processing, pp. 4583-4587, 2013

[6] E. Peixoto, T. Shanableh, and E. lzquierdo, "H.264/AVC to HEVC Video Transcoder Based on Dynamic Thresholding and Content Modeling," IEEE Transactions on Circuits and Systems for Video Technology, vol. 24, no. 1, pp. 99-112, 2014

[7] J. Daemen and V. Rijmen, "AES Proposal: Rijndael," 1999

[8] H. Lipmaa and P. Rogaway, "Comments to NIST Concerning AES-Modes of Operations: CTR Mode Encryption", 2000

[9] NIST, Secure Hash Standard, Draft FIPS PUB 180-4, 2001

[10] T. S. Parker and L. O. Chua, "Chaos: A Tutorial for Engineers," Proceedings of the IEEE, vol. 75, no. 8, pp. 982-1008, 1987

[11] F. Peng, X. Zhang, Z-X Lin, and M. Long, "A Tunable Selective Encryption Scheme for H.265/HEVC Based on Chroma IPM and Coefficient Scrambling," IEEE Transactions on Circuits and Systems for Video Technology, vol. 30, no. 8, pp. 2765-2780, 2020

[12] C. Chen, X. Wang, G. Liu, and G. Huang, "A Robust Selective Encryption Scheme for H.265/HEVC Video," IEEE Access, vol. 11, pp. 17252-17264, 2022

[13] 新一代高效影片編碼H.265/HEVC: 原理、標準與實現 / 萬帥, 楊付正編著. －北京: 電子工業出版社, 2014.12

[14] M. K. Lee and E. S. Jang, "Start Code-Based Encryption and Decryption Framework for HEVC," IEEE Access, vol. 8, pp. 202910-202918, 2020

[15] M. K. Lee and E. S. Jang, "Cryptanalysis of Start Code-Based Encryption Method for HEVC," IEEE Access, vol. 9, pp. 92568-92577, 2021

[16] G. V. Wallendael, A. Boho, J. D. Cock, A. Munteanu, and R. V. d. Walle, "Encryption for High Efficiency Video Coding with Video Adaptation Capabilities," IEEE International Conference on Consumer Electronics, vol. 59, no. 3, pp. 634-642, 2013

[17] A. I. Sallam, E-S M. El-Rabaie, and O. S. Faragallah, "CABAC-Based Selective Encryption for HEVC Using RC6 in Different Operation Modes," Multimedia Tools and Applications, pp. 28395-28416, 2018

[18] M. Farajallah, W. Hamidouche, O. Défforges, and S. E. Assad, "ROI Encryption for the HEVC Coded Video Contents," IEEE International Conference on Image Processing, pp. 3096-3100, 2015

[19] Q-J Zhang, Q. Ye, Z-M Yuan, and L. Li, "Fast HEVC Selective Encryption Scheme Based on Improved CABAC Coding Algorithm," IEEE 6th International Conference on Computer and Communications, pp. 1022-1028, 2020

[20] W. Wen, R. Tu, Y. Zhang, Y. Zhang, Y. Fang, and Y. Yang, "A Multi-Level Approach with Visual Information for Encrypted H.265/HEVC Videos," Multimedia Systems, vol. 29, no. 3, pp. 1073-1087, 2022

[21] C. Chen, X. Wang, G. Huang, and G. Liu, "An Efficient Video Encryption Algorithm Based on the Pseudorandom Number Generator of Zipf Distribution," Security and Communication Networks, pp. 1-16, 2022

[22] M. Yang, L. Zhuo, J. Zhang, and X. Li, "An Efficient Format Compliant Video Encryption Scheme for HEVC Bitstream," IEEE International Conference on Progress in Informatics and Computing, pp. 374-378, 2015

[23] D. Xu, "Commutative Encryption and Data Hiding in HEVC Video Compression," IEEE Access, vol. 7, pp. 66028-66041, 2019

[24] B. Boyadjis, C. Bergeron, B. Pesquet-Popescu, and F. Dufaux, "Extended Selective Encryption of H.264/AVC (CABAC) and HEVC Encoded Video Streams," IEEE Transactions on Circuits and Systems for Video Technology, vol. 27, no. 4, pp. 892-906, 2017

[25] B. Tang and C. Yang, "Feasibility Research of Luma Prediction Mode Encryption After HEVC Encoding," IEEE International Conference on Information Communication and Software Engineering, pp. 88-91, 2021

[26] Q-J Zhang, Q. Ye, L. Li, S-J Liu, and K-Q Chen, "An Efficient Selective Encryption Scheme for HEVC Based on Hyperchaotic Lorenz System," IEEE 5th Advanced Information Technology, Electronic and Automation Control Conference, pp. 683-690, 2021

[27] A. I. Sallam, E-S M. El-Rabaie, and O. S. Faragallah, "Efficient HEVC Selective Stream Encryption Using Chaotic Logistic Map," Multimedia Systems, vol. 24, no. 4, pp. 419-437, 2018

[28] B. Liu, J. Liu, S. Wang, M. Zhong, B. Li, and Y. Liu, "HEVC Video Encryption Algorithm Based on Integer Dynamic Coupling Tent Mapping," Journal of Advanced Computational Intelligence and Intelligent Informatics, vol. 24, no. 3, pp. 335-345, 2020

[29] Q. Ye, Q. Zhang, S. Liu, and K. Chen, "A Novel Chaotic System Based on Coupled Map Lattice and Its Application in HEVC Encryption," Mathematical Biosciences and Engineering, vol. 18, no. 6, pp. 9410-9429, 2021

[30] Q. Lu, C. Zhu, and X. Deng, "An Efficient Image Encryption Scheme Based on the LSS Chaotic Map and Single S-Box," IEEE Access, vol. 8, pp. 25664-25678, 2020

[31] H.265/HEVC: 影片編碼新標準及其擴展 / 朱秀昌, 劉峰, 胡棟編著. －北京:電子工業出版社, 2016.7

[32] HM 17.0 Github: https://vcgit.hhi.fraunhofer.de/jvet/HM/-/tree/HM-17.0

[33] YUV Video Sequences: https://media.xiph.org/video/derf/

[34] HEVC Test Sequences: http://ftp.kw.bbc.co.uk/hevc/hm-10.0-anchors/bitstreams/