Hiding data in spatial domain images with distortion tolerance

Data hiding is a technique that is used to embed secret information into a cover media. It has been widely used in protecting copyright and transmitting sensitive data over an insecure channel. Conventional data hiding schemes only focus on how to reduce the distortion when sensitive data is embedded into the cover image. However, the transmitted images may be compressed or occur transmitting errors. If such errors occur, the receiver cannot extract the correct information from the stego-image. In this paper, we proposed a novel hiding data scheme with distortion tolerance. The proposed scheme not only can prevent the quality of the processed image from being seriously degraded, but also can simultaneously achieve distortion tolerance. Experimental results show that the proposed scheme indeed can obtain a good image quality and is superior to the other schemes in terms of its distortion tolerance.     

Reversible data hiding based compressible privacy preserving system for color image

In digital era, privacy preservation and data size reduction are important issues and many applications handle them simultaneously. In this paper, authors introduce a novel application of reversible data hiding to protect privacy sensitive region in a color image while reducing its file size. The proposed work introduces entropy as a new performance criterion along with distortion, capacity for reversible data hiding. Evaluation metric of the proposed method is a file size of watermarked and losslessly compressed image. The proposed method preserves privacy and controls rise in image entropy by reversible data hiding.

     

Reversible privacy preserving data mining: a combination of difference expansion and privacy preserving

Privacy Preserving Data Mining (PPDM) can prevent private data from disclosure in data mining. However, the current PPDM methods damaged the values of original data where knowledge from the mined data cannot be verified from the original data. In this paper, we combine the concept and technique based on the reversible data hiding to propose the reversible privacy preserving data mining scheme in order to solve the irrecoverable problem of PPDM. In the proposed privacy difference expansion (PDE) method, the original data is perturbed and embedded with a fragile watermark to accomplish privacy preserving and data integrity of mined data and to also recover the original data. Experimental tests are performed on classification accuracy, probabilistic information loss, and privacy disclosure risk used to evaluate the efficiency of PDE for privacy preserving and knowledge verification.     

面向聚类的平面反射数据扰动方法

面向聚类的数据隐藏通常使用数据扰动技术防止敏感信息泄露。针对现有的面向聚类的数据扰动方法隐私保护度低的问题,提出一种基于平面反射的数据扰动方法,将发布对象的全部属性两两配对构成平面上的点,再随机选择一条直线,作每对属性关于直线的对称点,转换后的数据即为发布的数据。实验结果表明,这种方法具有较好的隐私保护度和聚类可用性,且对高维数据有良好的适应性。     

A fine-grained privacy protection data aggregation scheme for outsourcing smart grid

Compared with the traditional power grid, smart grid involves many advanced technologies and applications. However, due to the rapid development of various network technologies, smart grid is facing the challenges of balancing privacy, security, efficiency, and functionality. In the proposed scheme, we design a privacy protection scheme for outsourcing smart grid aided by fog computing, which supports fine-grained privacy-protected data aggregation based on user characteristics. The fog server matches the encrypted characteristics in the received message with the encrypted aggregation rules issued by the service provider. Therefore, the service provider can get more fine-grained analysis data based on user characteristics. Different from the existing outsourcing smart grid schemes, the proposed scheme can achieve real-time pricing on the premise of protecting user privacy and achieving system fault tolerance. Finally, experiment analyses demonstrate that the proposed scheme has less computation overhead and lower transmission delay than existing schemes.     

Multilevel reversible data hiding based on histogram modification of difference images

Reversible data hiding has drawn considerable attention in recent years. Reversibility allows original media to be completely recovered from marked media without distortion after embedded message has been extracted. In this paper we propose a multilevel reversible data hiding scheme based on the difference image histogram modification that uses the peak point to hide messages. Through a joint imperceptibility and hiding capacity evaluation, we show that our proposed scheme uses a multilevel hiding strategy to achieve large hiding capacity and keep distortion low. Performance comparisons with other existing reversible hiding schemes are provided to demonstrate the validity of our proposed scheme.     

数据库中的知识隐藏

伴随着数据共享、隐私保护、知识发现等多重需求而产生的PPDM(privacy preserving data mining),成为数据挖掘和信息安全领域近几年来的研究热点.PPDM中主要考虑两个层面的问题:一是敏感数据的隐藏与保护;二是数据中蕴涵的敏感知识的隐藏与保护(knowledge hiding in database,简称KHD).对目前的KHD技术进行分类和综述.首先介绍KHD产生的背景,然后着重讨论敏感关联规则隐藏技术和分类规则隐藏技术,接着探讨KHD方法的评估指标,最后归结出KHD后续研究的3个方向:数据修改技巧中基于目标距离的优化测度函数设计、数据重构技巧中的反向频繁项集挖掘以及基于数据抽样技巧的通用知识隐藏方法设计.     

隐私保护数据挖掘*

隐私保护数据挖掘的目标是寻找一种数据集变换方法,使得敏感数据或敏感知识在实施数据挖掘的过程中不被发现。近年出现了大量相关算法,按照隐私保持技术可将它们分为基于启发式技术、基于安全多方技术和基于重构技术三种。结合目前研究的热点对关联规则和分类规则的隐私保护数据挖掘进行介绍,并给出算法的评估方法,最后提出了关联规则隐私保护数据挖掘未来研究工作的方向。     

基于单向函数的无线传感器网络安全数据汇聚方案

为有效减少冗余数据传输,增强安全性,提出了一种基于单向函数的传感器网络安全数据汇聚方案,汇聚节点无须解密数据,利用单向函数完成数据完整性检查、身份认证、数据汇聚等,保证了端到端传输的数据私密性。与相关数据汇聚方案相比,除了具有较小的能耗开销,该方案还在抵抗主动攻击、节点妥协攻击及DoS攻击等恶意行为方面具有较高的安全性。     

一种改进的差分隐私参数设置及数据优化算法

基于差分隐私的数据扰动技术是当前隐私保护技术的研究热点,为了实现对敏感数据差分隐私保护的同时,尽量提高数据的可用性,对隐私参数的合理设置、对添加噪声后数据进行优化是差分隐私保护中的关键技术。提出了隐私参数设置算法RBPPA以及加噪数据的优化算法DPSRUKF。RBPPA将隐私参数设置构建于数据访问者和贡献者的信誉度之上,并与数据隐私度以及访问权限值关联,构造了细粒度的隐私参数设置方案; DPSRUKF采用了平方根无味卡尔曼滤波处理加噪数据,提高了差分隐私数据的可用性。实验分析表明,该算法实现了隐私参数的细粒化设置以及加噪数据优化后数据精度的提高,既为敏感数据的应用提供了数据安全保障,又为数据访问者提供了数据的高可用性。     

An improved lossless data hiding scheme based on image VQ-index residual value coding

Copyright protection and information security have become serious problems due to the ever growing amount of digital data over the Internet. Reversible data hiding is a special type of data hiding technique that guarantees not only the secret data but also the cover media can be reconstructed without any distortion. Traditional schemes are based on spatial, discrete cosine transformation (DCT) and discrete wavelet transformation (DWT) domains. Recently, some vector quantization (VQ) based reversible data hiding schemes have been proposed. This paper proposes an improved reversible data hiding scheme based on VQ-index residual value coding. Experimental results show that our scheme outperforms two recently proposed schemes, namely side-match vector quantization (SMVQ)-based data hiding and modified fast correlation vector quantization (MFCVQ)-based data hiding.     

Prediction-based reversible data hiding

For some applications such as satellite and medical images, reversible data hiding is the best solution to provide copyright protection or authentication. Being reversible, the decoder can extract the hidden data and recover the original image without distortion. In this paper, a reversible data hiding scheme based on prediction error expansion is proposed. The predictive value is computed by using various predictors. The secret data is embedded in the cover image by exploiting the expansion of the difference between a pixel and its predictive value. Experimental results show that our method is capable of providing a great embedding capacity without making noticeable distortion. In addition, the proposed scheme is also applicable to various predictors.     

A robust without intra-frame distortion drift data hiding algorithm based on H.264/AVC

This paper presents an improved robust data hiding algorithm based on BCH syndrome code (BCH code) technique and without distortion drift technique. The BCH code technique, which can correct the error bits caused by network transmission, packet loss, video-processing operations, various attacks, etc., encodes the embedded data by using BCH code before data hiding. The without distortion drift technique in this paper is that we exploit several paired-coefficients of a 4?×?4 discrete cosine transform (DCT) block to accumulate the embedding induced distortion, and the directions of intra-frame prediction are utilized to avert the distortion drift. It is proved analytically and shown experimentally that the new data hiding algorithm can get more robustness, effectively avert intra-frame distortion drift and get high visual quality.     

基于敏感项集动态隐藏的用户隐私保护方法*

时空k-匿名由于适应移动性环境以及实现更为简单方便等特点,是当前LBS领域中被使用最广泛的模型。由于LBS在线及动态的特性,使传统的数据变形或重构方法不足以对抗从大量时空k-匿名数据集挖掘到的关联规则的用户隐私攻击。针对以上问题提出了基于敏感项集动态隐藏的用户隐私保护方法（SIDH）：感知敏感规则对应项集空间的正负边界,增量扩展原始快照查询匿名集数据,以敏感项集的动态隐藏净化敏感关联规则,最终实现用户隐私保护。通过对2612辆出租车的GPS数据生成的匿名集进行敏感项集隐藏实验,结果表明：SIDH方法隐藏敏感项集的数量和速度明显高于传统匿名方法,并且不会新增敏感项集。因此SIDH方法更能有效应对匿名集敏感关联规则的推理攻击,副作用较小。     

MSDA: multi-subset data aggregation scheme without trusted third party

Data aggregation has been widely researched to address the privacy concern when data is published,meanwhile,data aggregation only obtains the sum or average in an area.In reality,more fine-grained data brings more value for data consumers,such as more accurate management,dynamic price-adjusting in the grid system,etc.In this paper,a multi-subset data aggregation scheme for the smart grid is proposed without a trusted third party,in which the control center collects the number of users in different subsets,and obtains the sum of electricity consumption in each subset,meantime individual user’s data privacy is still preserved.In addition,the dynamic and flexible user management mechanism is guaranteed with the secret key negotiation process among users.The analysis shows MSDA not only protects users’privacy to resist various attacks but also achieves more functionality such as multi-subset aggregation,no reliance on any trusted third party,dynamicity.And performance evaluation demonstrates that MSDA is efficient and practical in terms of communication and computation overhead.     

An encoding method for both image compression and data lossless information hiding

Reversible image data hiding technology means the cover image can be totally recovered after the embedded secret data is extracted. In this paper, we propose a reversible image data hiding scheme based on vector quantization (VQ) compressed images. The secret bits are embedded into the VQ index table by modifying the index value according to the difference of neighboring indices. The data hiding capacity and the size of the final codestream (embedded result) are a trade-off, and it can be decided by users. In other words, the proposed scheme has flexible hiding capacity ability. To estimate the performance, the proposed scheme was compared with the scheme proposed by Wang and Lu (2009). The results of the comparison showed that our proposed scheme is superior to the scheme proposed by Wang and Lu in both data hiding capacity and bit rate.     

A verifiable privacy-preserving data collection scheme supporting multi-party computation in fog-based smart grid

Incorporation of fog computing with low latency,preprocession(e.g.,data aggregation)and location awareness,can facilitate fine-grained collection of smart metering data in smart grid and promotes the sustainability and efficiency of the grid.Recently,much attention has been paid to the research on smart grid,especially in protecting privacy and data aggregation.However,most previous works do not focus on privacy-preserving data aggregation and function computation query on enormous data simultaneously in smart grid based on fog computation.In this paper,we construct a novel verifiable privacy-preserving data collection scheme supporting multi-party computation(MPC),named VPDC-MPC,to achieve both functions simultaneously in smart grid based on fog computing.VPDC-MPC realizes verifiable secret sharing of users’data and data aggregation without revealing individual reports via practical cryptosystem and verifiable secret sharing scheme.Besides,we propose an efficient algorithm for batch verification of share consistency and detection of error reports if the external adversaries modify the SMs’report.Furthermore,VPDC-MPC allows both the control center and users with limited resources to obtain arbitrary arithmetic analysis(not only data aggregation)via secure multi-party computation between cloud servers in smart grid.Besides,VPDC-MPC tolerates fault of cloud servers and resists collusion.We also present security analysis and performance evaluation of our scheme,which indicates that even with tradeoff on computation and communication overhead,VPDC-MPC is practical with above features.     

Adaptive real-time reversible data hiding for JPEG images

Data hiding used to embed data, such as copyright information, into various forms of media such as image, audio, or text with a minimum amount of perceivable degradation to the “host” signal. Therefore, in many cases, the cover media contain distortions even after the hidden data have been extracted. Thus, to extend the application of data hiding to some sensitive domains such as military, medical, and fine arts, which require the embedded cover images to be properly covered, reversible data hiding has become another new branch of this field. Our proposed scheme is inspired by Chang et al.’s idea. In this paper, we propose adaptive real-time reversible data hiding for JPEG images using successive zero coefficients in zigzag sequences of discrete cosine transformation blocks. The contribution of our proposed scheme successfully enhances the hiding capacity while the image quality of stego image and reversibility are maintained. The result of experiments conducted indicates that the proposed scheme enhances data hiding capacity, image quality, and improves performance.     

无线传感器网络中数据融合算法研究

在提供高效的数据融合的同时保障数据的安全是无线传感器网络的研究的一个具有挑战性的问题。本文为加法融合函数设计了一种具有隐私保护功能的数据融合算法——基于分簇的安全数据融合。该算法利用了分簇协议和多项式的代数性质。其优点为带来的通信开销较小。研究的主要目标是提高无线传感器网络中数据融合效率的同时,保证数据的安全性。     

一种基于Pairing的带有阈下信道的灵活数字签名方案

阈下信道是一种在公开信道中所建立的实现隐蔽通信的信道,它是一种典型的信息隐藏技术.通过结合数字签名和阈下信道技术,提出了一种基于双线性对的具有阈下信道的数字签名方案,并且在随机预言模型下证明该方案是安全的,其安全性是基于求解有限域上离散对数的困难性.该方案的一个主要特点是:同一个签名算法能够产生普通数字签名和具有阈下信道的数字签名,在正常情况下,签名者可以进行一般数字签名,如果需要阈下信道通信,签名者能够产生带有阈下信道的数字签名,非常方便签名者对阈下信道签名的灵活使用.