基于多项式划分的NTRU加密域可逆数据隐藏方案  

Reversible Data Hiding Scheme in NTRU Encrypted Domain Based on Polynomial Partition

作　　者：刘定财 吴昊天 庄振威 何军辉[1] LIU Dingcai;WU Haotian;ZHUANG Zhenwei;HE Junhui(School of Computer Science and Engineering,South China University of Technology,Guangzhou 510006,China)

机构地区：[1]华南理工大学计算机科学与工程学院,广州510006

出　　处：《计算机科学》2023年第8期294-303,共10页Computer Science

基　　金：国家自然科学基金(61772208);广东省自然科学基金(2021A1515011798)。

摘　　要：随着云计算技术的发展和隐私保护的需要,同态加密域中的可逆数据隐藏已成为一项研究热点。加密域可逆数据隐藏方案大多利用了图像中像素点之间的相关性及冗余,适用范围受到了一定的限制。为了提高数据隐藏方案的适用性和嵌入容量,针对NTRU(Number Theory Research Unit)加密系统,提出了一种基于多项式划分的可逆数据隐藏方案。该方案将NTRU加密系统中的多项式空间划分为用于表示原始载体的明文段和用于隐藏数据的数据隐藏段,可用于在多种加密的数字媒体中隐藏数据。接收者可以从密文中直接提取一部分隐藏的数据,并能从解密得到的明文中提取另一部分隐藏的数据,并无损地恢复原始明文。在实验部分,分别以灰度图像和文本为例,对所提算法的可行性进行验证。实验结果表明,对于一个以8比特表示的明文值,其密文中最多可以隐藏N-8比特的数据,其中N为NTRU加密系统中的参数;当N取503时,在一个密文中最多可以隐藏495比特的数据,并能无损地恢复出原始明文值。与现有的同类方案相比,该方案所提的NTRU域可逆数据隐藏算法具有较高的嵌入容量和较强的适用性。With the rapid development of cloud computing techniques and demand of privacy preservation,reversible data hiding(RDH)in homomorphic encrypted domain has become a hot research topic.Most of the existing RDH schemes in encrypted domain exploit correlations between adjacent pixels and redundancy in images,whose applications are limited.To improve applicabi-lity and embedding capacity,a new RDH scheme in NTRU encrypted domain based on polynomial partitioning is proposed.It divides the polynomial space in NTRU cryptosystem,which can be applied to multiple encrypted media content for data hiding.Part of the space is used to represent the original plaintext,while the rest space is used to hide the hidden data.The receiver can retrieve part of the hidden data directly from the ciphertext,while the rest hidden data can be extracted after decryption and the original plaintext can be correctly restored.In our experiments,grayscale images and text files are chosen to verify feasibility of the proposed scheme.Experimental results show that a maximum of N-8 bits can be hidden into a ciphertext for a plaintext represented with 8 bits,where N is a parameter used in NTRU cryptosystem.When N is set to 503,at most 495 bits can be hidden in a ciphertext while the plaintext can be exactly recovered.Compared with the existing schemes,the proposed scheme has higher embedding capacity and better applicability.

关 键 词：可逆数据隐藏 NTRU加密系统 多项式划分 无损恢复 嵌入容量 

分 类 号：TP391[自动化与计算机技术—计算机应用技术]