An Efficient Information Hiding Scheme Based on Closest Paired Tree Structure Vector Quantization

Information hiding schemes based on vector quantization(VQ) usually require lengthy VQ encoding and decoding processes.In this paper,we propose an efficient information hiding method based on closest paired tree structure vector quantization(CPTSVQ).The simulation result shows that the execution time of the proposed scheme is much shorter than that attained by previous approaches.

Load Balance Strategy of Data Routing Algorithm Using Semantics for Deduplication Clusters

The backup requirement of data centres is tremendous as the size of data created by human is massive and is increasing exponentially.Single node deduplication cannot meet the increasing backup requirement of data centres.A feasible way is the deduplication cluster,which can meet it by adding storage nodes.The data routing strategy is the key of the deduplication cluster.DRSS(data routing strategy using semantics) improves the storage utilization of MCS(minimum chunk signature) data routing strategy a lot.However,for the large deduplication cluster,the load balance of DRSS is worse than MCS.To improve the load balance of DRSS,we propose a load balance strategy used for DRSS,namely DRSSLB.When a node is overloaded,DRSSLB iteratively migrates the current smallest container of the node to the smallest node in the deduplication cluster until this overloaded node becomes non-overloaded.A container is the minimum unit of data migration.Similar files sharing the same features or file names are stored in the same container.This ensures the similar data groups are still in the same node after rebalancing the nodes.We use the dataset from the real world to evaluate DRSSLB.Experimental results show that,for various numbers of nodes of the deduplication cluster,the data skews of DRSSLB are under predefined value while the storage utilizations of DRSSLB do not nearly increase compared with DRSS,with the low penalty(the data migration rate is only6.5% when the number of nodes is 64).

Study of Difference-Expansion Embedding Schemes

Difference expansion(DE) is one of the famous schemes in the field of reversible data hiding.With the high efficiency and simplicity,DE also has received more attention over the years.DE has a good information capacity,but due to its major location map,the pure payload is rather low.Therefore many scholars did relevant improvements which let n pixels as a unit instead of the original two pixels as a unit and can adaptively adjust the number of embedding secret information according to the smoothness degree of the block,which achieves the result of improving the information payload or the image quality.In this paper,the study of DE-based reversible data hiding schemes is comprehensively discussed.The performance of DEbased schemes is evaluated and compared in terms of embedding capacity and stego-image quality.

Reversible Data Embedding Scheme Using Relationships between Pixel-Values and Their Neighbors

Reversible data embedding is becoming a very important issue in securing images transmitted over the Internet, especially in dealing with sensitive images such as those created for military data and medical data. Based on the relationships between pixels and their neighbors, we propose a reversible data embedding scheme to embed hidden messages into an original image. In our proposed scheme, a two-layer data embedding approach is used for our proposed data embedding phase. Layer-1 embedding is used to hide secret data. Layer-2 embedding, which is an embedding variant of the proposed layer-1 embedding, is used to hide side information, such as the parameters required to restore the marked image. In our layer-1 embedding, the value of an embedded pixel is determined according to a predetermined threshold and the relationship between the pixel and its neighbors. In our layer-2 embedding, the similar data embedding concept is expanded to the block-based. Experimental results provide supportive data to show that the proposed scheme can provide greater hiding capacity while preserving the image quality of a marked image in comparison with previous work.

High-Imperceptibility Data Hiding Scheme for JPEG Images Based on Direction Modification

Data hiding(DH)is an important technology for securely transmitting secret data in networks,and has increasing become a research hotspot throughout the world.However,for Joint photographic experts group(JPEG)images,it is difficult to balance the contradiction among embedded capacity,visual quality and the file size increment in existing data hiding schemes.Thus,to deal with this problem,a high-imperceptibility data hiding for JPEG images is proposed based on direction modification.First,this proposed scheme sorts all of the quantized discrete cosine transform(DCT)block in ascending order according to the number of non-consecutive-zero alternating current(AC)coefficients.Then it selects non-consecutive-zero AC coefficients with absolute values less than or equal to 1 at the same frequency position in two adjacent blocks for pairing.Finally,the 2-bit secret data can be embedded into a coefficient-pair by using the filled reference matrix and the designed direction modification rules.The experiment was conducted on 5 standard test images and 1000 images of BOSSbase dataset,respectively.The experimental results showed that the visual quality of the proposed scheme was improved by 1∼4 dB compared with the comparison schemes,and the file size increment was reduced at most to 15%of the comparison schemes.

A Steganography Based on Optimal Multi-Threshold Block Labeling

Hiding secret data in digital images is one of the major researchfields in information security.Recently,reversible data hiding in encrypted images has attracted extensive attention due to the emergence of cloud services.This paper proposes a novel reversible data hiding method in encrypted images based on an optimal multi-threshold block labeling technique(OMTBL-RDHEI).In our scheme,the content owner encrypts the cover image with block permutation,pixel permutation,and stream cipher,which preserve the in-block correlation of pixel values.After uploading to the cloud service,the data hider applies the prediction error rearrangement(PER),the optimal threshold selection(OTS),and the multi-threshold labeling(MTL)methods to obtain a compressed version of the encrypted image and embed secret data into the vacated room.The receiver can extract the secret,restore the cover image,or do both according to his/her granted authority.The proposed MTL labels blocks of the encrypted image with a list of threshold values which is optimized with OTS based on the features of the current image.Experimental results show that labeling image blocks with the optimized threshold list can efficiently enlarge the amount of vacated room and thus improve the embedding capacity of an encrypted cover image.Security level of the proposed scheme is analyzed and the embedding capacity is compared with state-of-the-art schemes.Both are concluded with satisfactory performance.

Online Maximum Loadability Monitoring Scheme for Smart Grid

This paper presents an algorithm based on Thevenin equivalent network for voltage stability evaluation. The proposed algorithm provides a technique for online predicting the largest possible margin to voltage collapse of an electrical power system. An online maximum loadability determination algorithm is developed by transforming the impedance margin, obtained from the Thevenin equivalent network, into the loading margin at each of the load buses in a power system. Furthermore, the proposed algorithm also takes system load trends into account for practical applications. The effectiveness of the proposed algorithm is tested on the IEEE 14 and 57 bus test systems. Simulation results have shown that the proposed algorithm is useful and practical for online voltage instability monitoring.

Fast Image Coding Algorithm Using Indirect-Index Codebook Based on SMVQ

Side-match vector quantization(SMVQ) achieves better compression performance than vector quantization(VQ) in image coding due to its exploration of the dependence of adjacent pixels. However, SMVQ has the disadvantage of requiring excessive time during the process of coding. Therefore, this paper proposes a fast image coding algorithm using indirect-index codebook based on SMVQ(IIC-SMVQ) to reduce the coding time. Two codebooks, named indirect-index codebook(II-codebook) and entire-state codebook(ES-codebook), are trained and utilized. The II-codebook is trained by using the Linde-Buzo-Gray(LBG) algorithm from side-match information, while the ES-codebook is generated from the clustered residual blocks on the basis of the II-codebook. According to the relationship between these two codebooks,the codeword in the II-codebook can be regarded as an indicator to construct a fast search path, which guides in quickly determining the state codebook from the ES-codebook to encode the to-be-encoded block. The experimental results confirm that the coding time of the proposed scheme is shorter than that of the previous SMVQ.

Protecting User Privacy in a Multi-Path Information-Centric Network Using Multiple Random-Caches

缓冲的在里面网络是信息中央的网络(ICN ) 为有效内容倡导的基本机制交货。然而，这新机制也由于缓存窥探带严肃的隐私风险攻击。这个问题的一个有效答案是随机缓存的，在在一个路由器的缓存随机模仿缓存的地方撞击或为每个内容的一个缓存失误请求 / 探查。在这份报纸，我们调查使用的有效性多重对随机缓存在一条多路径保护缓存隐私 ICN。我们为描绘多路径 ICN 的隐私与建议模型随机缓存，并且分析二不同攻击情形：1 ) 基于前缀的攻击并且 2 ) 基于后缀的攻击。同类、异构的缓存被考虑。我们的分析在多路径 ICN 显示出那一个对手罐头潜在地更增加由采用基于前缀的攻击的隐私信息。而且，异构的缓存比的提供好一些的隐私保护在两攻击下面的同类的。多路径的隐私上的不同参数的效果随机缓存进一步被调查，并且有它的单个路径的对应物的比较基于数字评估被执行。在这份报纸的分析和结果在设计并且评估多路径提供卓见 ICN 我们什么时候考虑隐私。

Enhanced Delegation Based Authentication Protocol for Secure Roaming Service with Synchronization

Portable communication systems can provide mobile users with global roaming services. Recently, Youn and Lim proposed a delegation-based authentication protocol which achieves unlinkability for secure roaming services. This paper indicates that there are two drawbacks in Youn and Lim's protocol: 1) the synchronization problem will lead to a fail in on-line authentication; and 2) the exhaustive search puts a heavy burden on the off-line authentication process. Moreover, based on Youn and Lim's protocol, a remedy is proposed to address these problems. It is worthwhile to note that the proposed remedy not only keeps the original advantages but also enhances the security and performance.

A Photo Certificate-A Framework for Generating Visualized Public Key Certificates

In the proposed photo certificate, the principal component is the image, for example, the user's photo. User-related fields, such as the subject's name, the issuer's name, and the expiration period, which are meaningful to users, are embedded into the surface of the photo by using a visible watermark algorithm, so that the reader can capture this information without the requirement for special software. The remaining fields in the certificate are embedded into a marked photo. Later, the whole photo certificate is cryptographically signed by certification authority (CA) private key to guarantee the integrity of our photo certificate. By such arrangement, the certificate's verification is divided into two layers. The first layer is human visual system oriented and the second layer is the software-oriented. User can determine whether the user's photo and its subject's name are consistent and check whether the expired period is valid first. The second layer's verification is lunched only when the first layer's verification is passed. To sum up, the proposed photo certificate not only inherits the functions of a traditional certificate, but also provides a friendlier operational environment of X.509 certificate.

Secret Sharing Using Visual Cryptography

Compared with the traditional cryptography,visual cryptography(VC) decrypts secret images referring to the characteristics of human vision,rather than the cryptography knowledge or complex computations.Furthermore,seeing to the freeness of the secret key,the whole process of encryption as well as decryption for the visual cryptography meets a fast dealing course.As to the security concern,it is able to guarantee that no one can have access to any clues about the content of a secret image from individual cover images.Thus,owing to the studies on this area,the target of light-weighted cryptography is reached.Now the visual cryptography has been developed from the meaningless shadows to the meaningful ones.Seeing to the highly developed technique,some advanced VC techniques are introduced in this survey,respectively.

Distortion-Free Data Embedding Scheme for High Dynamic Range Images

Distortion-free data embedding is a technique which can assure that not only the secret data is correctly extracted but also the cover media is recovered without any distortion after secret data is extracted completely.Because of these advantages,this technique attracts the attention of many researchers.In this paper,a new distortion-free data embedding scheme for high dynamic range(HDR) images is proposed.By depending on Cartesian product,this scheme can obtain higher embedding capacity while maintaining the exactly identical cover image and stego image when using the tone mapping algorithms.In experimental results,the proposed scheme is superior to Yu et al.'s scheme in regard to the embedding rate?an average embedding rate of 0.1355 bpp compared with Yu et al.'s scheme(0.1270 bpp).

A Visual Secret Sharing Scheme for Progressively Restoring Secrets

Visual secret sharing has received more and more attention over the past years due to the fact that neither complex computation nor cryptographic knowledge is required to decrypt the secret image directly according to the characteristics of the human vision system. Considering the issue of sharing the secret image at multiple image resolutions with the meaningful shadows, in this paper, we present a friendly progressive visual secret sharing scheme without expanding the image size in the shadows and the reconstructed secret image based on applying a 2?2-sized block-wise operation to generate the shadows block by block. The proposed method can achieve these benefits: 1) the generated shadows are meaningful, and their sizes are not expanded, and 2) the secret image can be recovered at different resolutions by stacking different quantities of shadows together. The experimental results also show that the proposed method is superior to other compared schemes.

A Novel(n,n)Secret Image Sharing Scheme Based on Sudoku

Recently, Chang et al. proposed a Sudoku-based secret image sharing scheme. They utilized the Sudoku grid to generate meaningful shadow images, and their scheme satisfied all essential requirements. Based on Chang et al.'s scheme, we propose a novel (n, n) secret image sharing scheme based on Sudoku. In the proposed scheme, a secret image can be shared among n different cover images by generating n shadow images, and the secret image can be reconstructed without distortion using only these n shadow images. Also, the proposed scheme can solve the overflow and underflow problems. The experimental results show that the visual quality of the shadow images is satisfactory. Furthermore, the proposed scheme allows for a large embedding capacity.

3D Multilayered Turtle Shell Models for Image Steganography

By embedding secret data into cover images,image steganography can produce non-discriminable stego-images.The turtle shell model for data hiding is an excellent method that uses a reference matrix to make a good balance between image quality and embedding capacity.However,increasing the embedding capacity by extending the area of basic structures of the turtle shell model usually leads to severe degradation of image quality.In this research,we innovatively extend the basic structure of the turtle shell model into a three-dimensional(3D)space.Some intrinsic properties of the original turtle shell model are well preserved in the 3D version.Theoretic analysis shows that the new proposed models have good performance both in the image quality and in the complexity of the reference matrix.Our experimental results justify the theoretic conclusions.

Sub-pixel change detection for urban land-cover analysis via multi-temporal remote sensing images

Conventional change detection approaches are mainly based on per-pixel processing,which ignore the sub-pixel spectral variation resulted from spectral mixture.Especially for medium-resolution remote sensing images used in urban landcover change monitoring,land use/cover components within a single pixel are usually complicated and heterogeneous due to the limitation of the spatial resolution.Thus,traditional hard detection methods based on pure pixel assumption may lead to a high level of omission and commission errors inevitably,degrading the overall accuracy of change detection.In order to address this issue and find a possible way to exploit the spectral variation in a sub-pixel level,a novel change detection scheme is designed based on the spectral mixture analysis and decision-level fusion.Nonlinear spectral mixture model is selected for spectral unmixing,and change detection is implemented in a sub-pixel level by investigating the inner-pixel subtle changes and combining multiple composition evidences.The proposed method is tested on multi-temporal Landsat Thematic Mapper and China–Brazil Earth Resources Satellite remote sensing images for the land-cover change detection over urban areas.The effectiveness of the proposed approach is confirmed in terms of several accuracy indices in contrast with two pixel-based change detection methods(i.e.change vector analysis and principal component analysis-based method).In particular,the proposed sub-pixel change detection approach not only provides the binary change information,but also obtains the characterization about change direction and intensity,which greatly extends the semantic meaning of the detected change targets.

New Sealed-Bid Electronic Auction with Fairness,Security and Efficiency

Electronic sealed-bid auction schemes usually have a common drawback,the third party(auction host)can conspire with a malicious bidder to leak all bidding prices before the opening stage.It results in the malicious bidder wining the auction with an optimal bidding price.Recently,Liaw et al.proposed an auction protocol for electronic online bidding in which they designed a deposit deduction certification for government procurement.However,it also has above mentioned flaw.Moreover,we further found that there were some extra security drawbacks in their protocol.First,the bidder can forge a bidding receipt to claim that he/she is a valid auction winner.Second,it may suffer from the third party forging attack.Third,their protocol leaked some bidders' private information to the third party,such as the bidder's bank account number and the authorization code.Thus,it cannot protect the bidder's privacy at all.In this paper,we not only point out the drawbacks from the previous scheme but also propose a new electronic auction scheme to overcome the above mentioned drawbacks.Furthermore,the computational complexity can be decreased in our online sealed-bid auction scheme.

Blockchain-based Internet of Musical Things

Blockchain technology is impacting several industries,including the creative industries and those operating in the Internet of Things(IoT).Lately,researchers'attention has been devoted to the application of blockchain in the recorded music industry.However,thus far,no research has investigated the use of such technology in the Internet of Musical Things(IoMusT).The IoMusT is a new area emerging in industry and academy as an extension of the IoT to the musical domain.The IoMusT itself,as the IoT,is a distributed network of musical things,which are objects augmented with information and communication technologies serving a musical purpose.The IoMusT vision requires,above all,IoT features such as decentralization,seamless authentication,transparency,data integrity and privacy,and self-maintenance,as well as the musical domain features such as efficient handling of copyrights and speed of royalties payment.Such features can be brought by blockchain.In this paper,we investigate the integration of blockchain technology with the IoMusT,and we name such synthesis“Blockchain-based IoMusT”.We present a vision for this new paradigm in terms of the novel opportunities that are enabled,and we propose a set of application scenarios enabled by technological integration.Finally,we outline the open research directions in this promising area.