密文域可逆信息隐藏综述

可逆信息隐藏是信息隐藏技术的新兴研究方向，密文域可逆信息隐藏作为加密域信号处理技术与信息隐藏技术的重要结合点，对于数据处理过程中的信息安全可以起到双重保险的作用，尤其随着云服务的推广，密文域可逆信息隐藏是实现云环境下隐私保护的研究重点之一。针对当前密文域可逆信息隐藏技术的技术要求，介绍了该技术的产生发展背景，指出并分析了当前的技术难点，通过对各种类型代表性算法的研究，对密文域可逆信息隐藏技术进行了系统的分类，分析了不同嵌入方式的技术特点、实现框架与应用上的局限性。最后，结合密文域可逆信息隐藏的技术需求与难点，提出几点该领域未来的热点方向。

Overview on reversible data hiding in encrypted domain

Reversible data hiding is a new research direction of information hiding technology. Reversible data hiding in encrypted domain is a significant point which combines the technologies of the signal processing in encrypted domain and information hiding and can play an important role of double insurance for information security in data processing. In particular with the adoption of cloud services, reversible data hiding in encrypted domain has become a focused issue to achieve privacy protection in the cloud environment. Concerning the current technical requirements, the background and the development of reversible data hiding were introduced in encrypted domain, and the current technical difficulties were pointed out and analysed. By studying on typical algorithms of various types, the reversible data hiding algorithms in encrypted domain were systematically classified and their technical frameworks, characteristics and limitations of different applications were analysed. Finally, focused on the technology needs and difficulties, several future directions in this field were proposed.