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Storing only one unique copy of the same cloud data and guaranteeing its integrity are two main goals for cloud storage auditing and deduplication schemes. In such schemes, data owners can firmly believe the data integrity by periodically auditing and the cloud server can save lots of storage space by exploiting the duplication techniques. However, when a data owner deletes or modifies his outsourced data, he should lose the ownership for the original data and should not be able to successfully retrieve this data any more. For all we know, existing cloud storage auditing and deduplication literatures fail to support the modifications of ownership, which actually occur quite often in actual cloud storage scenarios. In this paper, we propose the first deduplicated data integrity auditing scheme supporting the ownership modification. It guarantees the integrity of the outsourced data and supports the dynamic access control over the outsourced data. We employ a re-encryption algorithm and the secure identity-based broadcast encryption technology, which prevent data from being disclosed to the revoked owners, even if they previously had prior ownership of these data. The security and efficiency of our proposed scheme have been validated by detailed analysis and experiments. [ABSTRACT FROM AUTHOR]

Using cloud storage, users can remotely store their data without the burden on complicated local storage management and maintenance. However, users will no longer physically possess the storage of their data after they upload the data to the cloud. It is very natural for users to suspect whether their data stored in the cloud is intact. To help users efficiently check the integrity of the outsourced data, many public auditing schemes have been proposed. Recently, Huang et al. have proposed a privacy-preserving public auditing scheme for non-manager group shared data. In this paper, we find a security flaw in their auditing scheme. Even if the cloud has deleted or polluted the whole outsourced data, it still can pass the verification of the verifier. And then, we overcome this shortcoming by improving their scheme, which prevents the cloud forging a valid proof to pass the integrity auditing. Last, we perform the concrete implementation of our improved scheme and Huang et al. 's scheme. [ABSTRACT FROM AUTHOR]

In recent years, Industrial Internet of Things (IIoT) has gradually attracted the attention of the industry owing to its accurate time synchronization, communication accuracy, and high adaptability. As an important data structure, graphs are widely used in IIoT applications, where entities and their relationships can be expressed in the form of graphs. With the widespread adoption of IIoT and cloud computing, an increasing number of individuals or organizations are outsourcing their IIoT graph data to cloud servers to enjoy the unlimited storage space and fast computing service. To protect the privacy of graph data, graphs are usually encrypted before being outsourced. In this article, we propose a search pattern privacy system for approximate shortest distance query of encrypted graphs in IIoT. To realize search pattern privacy, we adopt two noncolluded cloud servers to accomplish different tasks. We leverage the first server to store the encrypted data and perform query operations, and use the second one to rerandomize the contents and shuffle the locations of the queried records. Before queries, we generate the trapdoors by using different random numbers. After queries, we ask the second server to rerandomize the contents of the records that the first server touched. In addition, we shuffle the physical locations of original records by inserting some fake records. In this way, all contents and physical locations of the touched records change, so that the first server cannot distinguish whether two queries are the same or not. To enhance the efficiency on the user side, we further improve this system by moving some heavy workloads from the user to the cloud. The security analysis and the performance evaluation show that our work is secure and efficient. [ABSTRACT FROM AUTHOR]

A novel quasi-one-dimensional (Q1D) compound KNi 5 Bi 5.6 has been synthesized and its crystal structure has been determined by X-ray crystallography. The structure contains double-walled anionic nanowires [Ni 5 Bi 5.6 ]− separated by potassium cations. KNi 5 Bi 5.6 forms a new series of compounds together with previously reported Bi 5. 6 Ni 5 I and Bi 28 Ni 25 featuring [Ni 5 Bi 5.6 ] x (x = 1+, 0, 1−) nanowires for which the charge can be cationic, neutral or anionic without appreciably affecting the structure and composition. This unique characteristic provides a new platform to investigate charge invertible Q1D transition metal systems. Resistivity measurement of KNi 5 Bi 5.6 reveals a metallic type of conductivity. Magnetic susceptibility obeys a modified Curie-Weiss behavior with a small average effective magnetic moment of Ni and shows a weak magnetic anisotropy. A novel quasi-one-dimensional (Q1D) compound of KNi 5 Bi 5.6 features infinite anionic double-walled nanowire [Ni 5 Bi 5.6 ]− separated by K+ cations. The scanning electron microscopy image of KNi 5 Bi 5.6 crystals shows the fibers nature of KNi 5 Bi 5.6. As compared to previously reported Bi 5·6 Ni 5 I and Bi 28 Ni 25 , the columns [Ni 5 Bi 5.6 ] have the same stoichiometry and essentially the same structure but different forms of charge. The infinite columns of [Ni 5 Bi 5.6 ] x (x = 1+, 0, 1−) present an exotic case for which the charge can be cationic, neutral and anionic while their structure and composition are almost unaffected. [Display omitted] • A novel quasi-one-dimensional compound KNi 5 Bi 5.6 has been discovered. • KNi 5 Bi 5.6 contains double-walled anionic nanowires [Ni 5 Bi 5.6 ]−. • The charge of [Ni 5 Bi 5.6 ] x (x = 1+, 0, 1−) nanowires is invertible. [ABSTRACT FROM AUTHOR]

Two new transition metal fluoroselenides Ba 3 F 2 M Se 3 (M ​= ​Zn, Cd) have been successfully synthesized by solid-state reaction. Both compounds adopt the same crystal structure with orthorhombic space group Pnma (No. 62), consisting of an infinite corner-sharing [ M Se 3 ]4- anion chain separated by [Ba 3 F 2 ]4+ cationic chain of the fluorite type. Ba 3 F 2 ZnSe 3 and Ba 3 F 2 CdSe 3 show paramagnetic behaviors from 1.8 to 300 ​K due to the absence of magnetic transition metals. Their Debye temperatures are 170 ​K and 163 ​K, respectively, determined from the low-temperature specific heat measurements. The diffuse-reflectance spectroscopy measurements reveal that these new compounds are semiconductors with optical band gaps of 1.80 ​eV and 1.69 ​eV for Ba 3 F 2 ZnSe 3 and Ba 3 F 2 CdSe 3 , which are consistent with the band gaps obtained from the first-principle calculations. Two new low-dimensional Ba 3 F 2 M Se 3 (M ​= ​Zn, Cd) compounds were synthesized by solid-state reaction, which are composed of infinite corner-sharing [ M Se 3 ]4- chains separated by [Ba 3 F 2 ]4+ cationic chains of the fluorite type. The diffuse-reflectance spectroscopy measurements reveal that they are direct-gap semiconductors. [Display omitted] • Transition metal fluoroselenides Ba 3 F 2 M Se 3 were synthesized by solid-state reaction. • Ba 3 F 2 M Se 3 are composed of an infinite corner-sharing [ M Se 3 ]4- chain and [Ba 3 F 2 ]4+ cationic chain. • Ba 3 F 2 M Se 3 are direct-gap semiconductors with optical band gaps. [ABSTRACT FROM AUTHOR]