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In recent years, edge-cloud computing is regarded as a promising solution to meet the requirements of mobile computing and Internet-of-Things (IoT). However, due to the limited storage resources of edge equipment, there is a security threat when users outsource their sensitive data to the cloud computing center. The users usually adopt a data-encryption approach, Oblivious RAM (ORAM), which enables a user to read/write her outsourced private data without access pattern leakage. Not all users like the fully functional ORAM all the time since the ORAM protocol is usually highly interactive or occupies large edge storage space. We show that forward-private/backward-private (FP/BP) ORAMs are good alternatives for secure storage outsourcing. We introduce the FP/BP-ORAM definitions and present LL-ORAM, the first FP/BP-ORAM that achieves near-zero edge storage, single-round-trip read/write, and worst-case sublinear access time. For any outsourced record, LL-ORAM provides both an oblivious-access interface and a nonoblivious-access interface. FP-ORAM concerns more data-write privacy than data-read privacy. BP-ORAM concerns more data-read privacy. The constructions involve a tree data structure named LL-tree, which supports fast computation in the cloud with an access-pattern-reduced leakage profile. The security analysis shows that LL-ORAM meets the proposed forward and backward security model. The experimental results demonstrate that LL-ORAM is round-efficient and can be deployed on edge-cloud computing systems. • We give the security definitions of forward-private ORAMs and backward-private ORAMs. • We propose an approach of accessing private data both obliviously and nonobliviously. • We present an FP/BP-ORAM implementation. [ABSTRACT FROM AUTHOR]

A chaotic discrete Fresnel transform (DFnT) precoding scheme is proposed for physical-layer security enhancement in orthogonal frequency division multiplexing passive optical networks (OFDM-PONs). A multi-fold OFDM data encryption is applied in terms of the chaotic scale factor, and chaotic row/column permutations in the DFnT matrix, and the chaos sensitivity creates a huge key space of 1 0 138 . The peak-to-average power ratio (PAPR) performances of OFDM signals associated with a scale factor in DFnT are fully analyzed. A 38.2 Gb/s OFDM signal transmission with chaotic DFnT is successfully demonstrated over a 20 km standard single-mode fiber (SSMF), where the gain of receiver sensitivity is ∼ 2 dB (BER @ 10 − 3), compared with OFDM without precoding. • The first chaotic discrete fresnel transform (DFnT) is proposed for secure OFDM-PON. • A gain of receiver sensitivity of ∼ 2 dB at the BER of 10 − 3 and a huge key space of 1 0 138 are created. • The PAPRs of OFDM signals varying with the scale factor is analyzed. • The security provided by chaotic scale factor is fully analyzed. [ABSTRACT FROM AUTHOR]

[Display omitted] The exploration of carbon dots (CDs) with high quantum yield, facile synthesis path and satisfying output for their multiple applications remains a challenge. Thus, a silicon-doped orange-emitting carbon dots (O-CDs) is synthesized via a one-step hydrothermal method o-phenylenediamine and ethyl orthosilicate as raw materials. The O-CDs exhibits a bright and non-excitation-dependent emission peaking at 580 nm, and the corresponding quantum yield could be greatly boosted from 39.2 % to 64.1 % by silicon doping. The obtained O-CDs possess good biocompatibility and promising luminescence stability with varying solvents, ionic concentrations and temperatures. Its bio-imaging ability is performed by incubating zebrafish embryos with O-CDs aqueous solution, and clear in-vivo fluorescent images are obtained. Furthermore, due to its high-efficient and specific pH-sensitive emission with excellent dispersibility, the O-CDs can be used as a fluorescent ink for dual-model data encry/decryption in both hand-writing and stamp printing. Therefore, the as-prepared O-CDs show the potential as promising candidate for biomedical diagnosis, data encryption, and anti-counterfeiting. [ABSTRACT FROM AUTHOR]

The powerful resource advantage of the cloud provides a suitable computing environment for data processing. By transferring local computing to the cloud, the efficiency of data processing can be improved. However, the open cloud environment has defects in data privacy-preserving. In order to strengthen the protection of data privacy and ensure the security of multi-party interaction, we propose a privacy-preserving multi-party computing scheme for K-means clustering (PPMCK). PPMCK can preserve data privacy in the cloud and in the local side for each party from multi-party computing. In addition, PPMCK uses homomorphic encryption to protect data privacy. To support the division operation and ciphertext value size comparison with which homomorphic encryption cannot handle, the corresponding measurements are adopted, which make homomorphic encryption work smoothly. The experimental results demonstrate that PPMCK is effective in both data processing and privacy-preserving. • Privacy-preserving security multiparty computing k-means clustering algorithm is proposed. • The computing efficiency is improved by transferring most of the calculations to the cloud. • The operations of ciphertext division and ciphertext comparison are supported. [ABSTRACT FROM AUTHOR]

Services computing can offer a high-level abstraction to support diverse applications via encapsulating various computing infrastructures. Though services computing has greatly boosted the productivity of developers, it is faced with three main challenges: privacy and security risks, information silo, and pricing mechanisms and incentives. The recent advances of blockchain bring opportunities to address the challenges of services computing due to its build-in encryption as well as digital signature schemes, decentralization feature, and intrinsic incentive mechanisms. In this paper, we present a survey to investigate the integration of blockchain with services computing. The integration of blockchain with services computing mainly exhibits merits in two aspects: i) blockchain can potentially address key challenges of services computing and ii) services computing can also promote blockchain development. In particular, we categorize the current literature of services computing based on blockchain into five types: services creation, services discovery, services recommendation, services composition, and services arbitration. Moreover, we generalize Blockchain as a Service (BaaS) architecture and summarize the representative BaaS platforms. In addition, we also outline open issues of blockchain-based services computing and BaaS. • Exploring the integration of blockchain with services computing. • Solving information silo, privacy-leakage, pricing issues of services computing. • Investigating opportunities and challenges of Blockchain-as-a-Service. [ABSTRACT FROM AUTHOR]

Encryption is an important technique to improve information security for many real-world applications. The Advanced Encryption Standard (AES) is a widely-used efficient cryptographic algorithm. Although AES is fast both in software and hardware, it is time-consuming to do data encryption especially for large amount of data. Therefore, it is a lasting effort to accelerate AES operations. This paper presents SW-AES, a parallel AES implementation on the Sunway TaihuLight, one of the fastest supercomputers in the world that takes the SW26010 processor as the basic building block. According to the architectural features of SW26010, SW-AES exploits parallelism from different levels, including (1) inter-CPE (Computing Processing Element) data parallelism that distributes tasks among the 256 on-chip CPEs, (2) intra-CPE data parallelism enabled by the Single-Instruction Multiple-Data (SIMD) instructions inside each CPE, and (3) instruction-level parallelism that pipelines memory access and the computation. In addition, corresponding to the two application scenarios, SW-AES presents scalable ways to efficiently run AES on many nodes. As a result, SW-AES can gain a maximum throughput of 13.50 GB/s on a single SW26010 node, which is 216.23 × higher than the latest parallel AES implementation on the Sunway TaihuLight, and about 37.3% higher than the latest AES implementation on the GTX 480 GPU. When running on 1024 computing nodes with each one processing 1 GB data, SW-AES can achieve a throughput of 13819.25 GB/s. On the contrast, only a throughput of 63.91 GB/s can be achieved by the latest related work on the Sunway TaihuLight. • A data layout enabling SIMD operations inside one Computing Processor Element. • An S-Box lookup strategy improving the performance of nonvectorized memory access. • A data parallelism to fully use the 256 Computing Processor Elements on a chip. • New mechanisms to scale AES operations of different scenarios to many nodes. [ABSTRACT FROM AUTHOR]

Here we consider a common data encryption problem encountered by users who want to disclose some data to gain utility but preserve their private information. Specifically, we consider the inference attack, in which an adversary conducts inference on the disclosed data to gain information about users' private data. Following privacy funnel (Makhdoumi et al., 2014), assuming that the original data X is transformed into Z before disclosing and the log loss is used for both privacy and utility metrics, then the problem can be modeled as finding a mapping X → Z that maximizes mutual information between X and Z subject to a constraint that the mutual information between Z and private data S is smaller than a predefined threshold ϵ. In contrast to the original study (Makhdoumi et al., 2014), which only focused on discrete data, we consider the more general and practical setting of continuous and high-dimensional disclosed data (e.g., image data). Most previous work on privacy-preserving representation learning is based on adversarial learning or generative adversarial networks, which has been shown to suffer from the vanishing gradient problem, and it is experimentally difficult to eliminate the relationship with private data Y when Z is constrained to retain more information about X. Here we propose a simple but effective variational approach that does not rely on adversarial training. Our experimental results show that our approach is stable and outperforms previous methods in terms of both downstream task accuracy and mutual information estimation. • Propose a simple but effective algorithm for privacy funnel optimization. • Analyze influence to privacy cost caused by the variational approach. • The extent to trade off between privacy leaking and data distortion. • Evaluation by downstream task accuracy on a well-known multi-task dataset. • Evaluation by mutual information estimator and other proxies. [ABSTRACT FROM AUTHOR]

• Chaotic Arnold transform and chirp matrix scheme to improve performance of OFDM-PON. • This scheme can improve sensitivity, and higher scrambling degree, lower correlation. • As such, we believe that this manuscript can meet the outstanding standards of Optical Fiber Technology, and it could be of interest to a broad readership. In this paper, we first propose and experimentally demonstrate an encryption scheme by combining the chaotic Arnold transform (CAT) and chaotic chirp matrix (CCM) techniques in orthogonal frequency division multiplexing passive optical network (OFDM-PON) system to simultaneously enhance physical-layer security and system transmission performance. In this system, the CAT is employed to scramble quadrature amplitude modulation (QAM) symbols in the time-frequency domain, thereby obtaining data encryption. Moreover, the CCM is designed to reduce the peak-to-average power ratio (PAPR) of OFDM signals and further enhance the system security. With these processing techniques, ∼10712 key space can be created to protect against exhaustive trials. A 10-Gb/s encrypted 16-QAM-based OFDM signal transmission is successfully demonstrated over a 20-km single mode fiber (SMF) by experiment. The results show that, our proposed method can achieve ∼2-dB PAPR reduction and ∼1.2-dB sensitivity improvement compared with the common OFDM-based PON system. Therefore, it can be considered a promising candidate for physical security enhancement in future OFDM-PON. [ABSTRACT FROM AUTHOR]

Abstract Secret sharing is a mechanism by which a trusted dealer holding a secret "splits" the secret into many "shares" and distributes the shares to a collection of parties. Associated with the sharing is a monotone access structure, that specifies which parties are "qualified" and which are not: any qualified subset of parties can (efficiently) reconstruct the secret, but no unqualified subset can learn anything about the secret. In the most general form of secret sharing, the access structure can be any monotone NP language. In this work, we consider two very natural extensions of secret sharing. In the first, which we call distributed secret sharing, there is no trusted dealer at all, and it can be thought of as combining the features of multiparty non-interactive key exchange and standard secret sharing. Qualified sets can agree on a key which remains pseudorandom for unqualified sets. Our second notion is called functional secret sharing, which incorporates some of the features of functional encryption into secret sharing by providing more fine-grained access to the secret. Qualified subsets of parties do not learn the secret, but instead learn some function applied to the secret, with each set of parties potentially learning a different function. Our main result is that both of the extensions above are equivalent to several recent cutting-edge primitives. In particular, general-purpose distributed secret sharing is equivalent to witness PRFs, and general-purpose functional secret sharing is equivalent to indistinguishability obfuscation. Thus, our work shows that it is possible to view some of the recent developments in cryptography through a secret sharing lens, yielding new insights about both these cutting-edge primitives and secret sharing. [ABSTRACT FROM AUTHOR]

Abstract Locally recoverable codes are error-correcting codes allowing local recovery of lost encoded data in a codeword. We give a method to construct locally recoverable codes from rational maps between affine spaces, whose fibres are used as recovery sets. The recovery of erasures is carried out by Lagrangian interpolation in general and simply by one addition in some good cases. We first state the general construction of these codes and study its main properties. Next we apply it to several types of codes, including algebraic geometry codes, Reed–Muller, and other related codes. The existence of several recovering sets for the same coordinate and the possibility of recover more than one erasure at the same time are also treated. [ABSTRACT FROM AUTHOR]

This paper proposes a multilevel reversible data hiding scheme in encrypted domain by utilizing the controllable redundancy of learning with error public key cryptography. Messages can be embedded into multilevel sub-regions of ciphertext by quantifying the encrypted domain and recoding its redundancy. We recode redundancy based on the characteristics of cipher’s distribution. Extraction and decryption processes are separated by dividing the encrypted domain into multilevel sub-regions and introducing different quantification standards. Original plaintext can be losslessly recovered from the marked ciphertext by using the decryption key; with a specific level data-hiding key, only the message hiding in the corresponding level can be extracted, while plaintext and other messages remain secret. We provide theoretical analysis and experimental results on the feasibility, reversibility, and security of the proposed scheme. The capacity and encryption blow up factor are discussed. The experimental results demonstrate the maximum embedding rate can exceed 0.3000 bpb of ciphertext. [ABSTRACT FROM AUTHOR]

This letter proposes a modified discrete Fourier transform (DFT) encryption scheme with multi-dimensional chaos for the physical layer security and peak-to-average power ratio (PAPR) reduction in orthogonal frequency division multiplexing passive optical network (OFDM-PON) system. This multiple-fold encryption algorithm is mainly composed by using the column vectors permutation and the random phase encryption in the standard DFT matrix, which can create ∼10 551 key space. The transmission of ∼10 Gb/s encrypted OFDM signal is verified over 20-km standard single mode fiber (SMF). Moreover, experimental results show that, the proposed scheme can achieve ∼2.6-dB PAPR reduction and ∼1-dB improvement of receiver sensitivity if compared with the common OFDM-PON. [ABSTRACT FROM AUTHOR]

Reversible visual transformation reversibly transforms a secret image to a freely-selected target image and gets a camouflage image similar to the target image, which has been proved to be very useful in such two applications: privacy protection of images and reversible data hiding in encrypted images. Now, a new reversible transformation technique for color images is proposed by exploring and utilizing the correlations among three color channels and inside each color channel. The amount of the accessorial information for recording transformation parameters is largely reduced. Therefore, the visual quality of the created camouflage image is much improved by dividing the secret image and the target image into even smaller blocks for transformation. [ABSTRACT FROM AUTHOR]

Internet of things (IoT) applications comprising thousands or millions of intelligent devices or things is fast becoming a norm in our inter-connected world, and the significant amount of data generated from IoT applications is often stored in the cloud. However, searching encrypted data (i.e. Searchable Encryption—SE) in the cloud remains an ongoing challenge. Existing SE protocols include searchable symmetric encryption (SSE) and public-key encryption with keyword search (PEKS). Limitations of SSE include complex and expensive key management and distribution, while PEKS suffer from inefficiency and are vulnerable to insider keyword guessing attacks (KGA). Besides, most protocols are insecure against file-injection attacks carried out by a malicious server. Thus, in this paper, we propose an efficient and secure searchable encryption protocol using the trapdoor permutation function (TPF). The protocol is designed for cloud-based IoT (also referred to as Cloud of Things – CoT) deployment, such as Cloud of Battlefield Things and Cloud of Military Things. Compared with other existing SE protocols, our proposed SE protocol incurs lower computation cost at the expense of a slightly higher storage cost (which is less of an issue, considering the decreasing costs of storage). We also prove that our protocol achieves inside KGA resilience, forward privacy, and file-injection attack resilience. [ABSTRACT FROM AUTHOR]

With the emerging of the cloud computing, secure search over encrypted cloud data has become a hot research spot. Previous schemes achieve weaker query privacy-preserving ability due to the limitations of query trapdoor generation mechanisms. In these schemes, a data owner usually knows fully well the query contents of data users and a data user can also easily analyze query contents of another data user. In some application scenarios, the data user may be unwilling to leak their query privacy to anyone else except himself. We propose a privacy-enhanced search scheme by allowing the data user to generate random query trapdoor every time. We leverage Bloom filter and bilinear pairing operation to construct secure index for each data file, which enables the cloud to perform search without obtaining any useful information. We prove that our scheme is secure and extensive experiments demonstrate the correctness and practicality of the proposed scheme. [ABSTRACT FROM AUTHOR]

Anomaly detection on large-scale, complex and dynamic data is an essential service that is vital to enable smart functionality in most systems. Increased reliance on cloud computing infrastructures to process such data pose critical challenges with regard to security and privacy. This paper introduces a practical framework that takes advantage of cloud resources to provide a lightweight and scalable privacy preserving anomaly detection service for sensor data. A lightweight Homomorphic Encryption scheme is used to ensure data security and privacy with any computational limitations overcome through a convenient data processing model that employs a single private server collaborating with a set of public servers within a cloud data centre. Virtual nodes implemented on public servers perform granular anomaly detection operations on encrypted data. Comprehensive experimentation demonstrates consistently high detection accuracy with less overheads in a cloud-based anomaly detection model that is both lightweight and scalable while ensuring data privacy. [ABSTRACT FROM AUTHOR]

Attribute-based encryption (ABE) is recommended by the Cloud Security Alliance (CSA) as one of the possible cryptographic tools for access control in big data applications. In ABE, the shared file can be encrypted with the specific policy only once, and it can be decrypted by any receiver whose attributes are satisfied. When ABE is deployed in some open network scenarios, it is inevitably attacked by side channel attacks, because the big data are coming from diverse end-points. In this paper, we propose leakage resilient CP-ABE and KP-ABE schemes in the improved auxiliary input model, which allows the attacker query more leakage information regarding the encryption randomness after seeing the challenge ciphertext. Moreover, we construct an improved strong extractor from the modified Goldreich–Levin theorem for the security proof and prove that our scheme security relies on the Wang et al. construction. [ABSTRACT FROM AUTHOR]

The traditional data publishing methods will remove the sensitive attributes and generate the abundant records to achieve the goal of privacy protection. In the big data environment, the requirement of utilizing data (e.g., data mining) become more and more various, which is beyond the scope of the traditional method. This paper provides a cryptographic data publishing system that preserves the data integrity (i.e., the original data structure is preserved) and achieves anonymity without deletion of any attribute or utilization of redundancy. The security analysis shows that our system is secure under our proposed security model. [ABSTRACT FROM AUTHOR]

With recent trends in big data and cloud computing, data mining has also attracted considerable interest due to its potential to deal with distributed data in the cloud. However, existing data mining technologies may not be directly deployed as we need to avoid accidental privacy disclosure when data from different sources are mined. In this paper, we propose a secure and flexible cloud-assisted association rule mining over horizontally partitioned databases. Using the proposed scheme, data owners can provide their data and mine the association rules in the cloud flexibly, while being assured of minimal risks of privacy leakage. We then show that our proposed scheme achieves privacy-preserving mining of association rules, and provides resilience against collusion attacks. A comparative summary demonstrates that the proposed scheme is more efficient, in terms of computational costs, relative to several existing homomorphic-encryption-based schemes. [ABSTRACT FROM AUTHOR]

The optimal PPVO-based reversible data hiding (RDH) including adaptive prediction pattern and optimal bin selection is proposed in this paper. By reasonably designing the prediction pattern, each to-be-embedded pixel can be predicted by the n ( n ∈ { 4 , … , 13 } ) neighbors surrounding it. The larger n , the more accurate the prediction, and the higher embedding performance is achieved at low embedding capacity (EC) and vice versa. Since the neighbors surrounding each to-be-embedded pixel can be used for measuring the local complexity, the smoothness classification is more accurate, and furthermore, the prediction performance is increased. Two-stage embedding is exploited in this paper so as to ensure the implementation of full-enclosed-based prediction. Instead of treating separately two stages like in existing methods, two stages are treated jointly to optimize the selection of embedding bins at a given EC. In this way, the optimal embedding bins which can achieve as high visual quality as possible is obtained. Extensive experiments verify the proposed method is effective. [ABSTRACT FROM AUTHOR]

An involution is a permutation whose compositional inverse is itself. Differentially 4-uniform involutions with high algebraic degree and high nonlinearity are important for the design of block ciphers because they possess good cryptographic properties and the same component can be used in both encryption circuit and decryption circuit. A well known differentially 4-uniform involution is the multiplicative inverse function, which is used as the S-boxes in AES and Camellia. Although many differential 4-uniform permutations have been constructed, there are only a few classes of differentially 4-uniform involutions. Recently, Charpin et al. presented an idea of constructing involutions, which is called piece by piece construction. With this method, we construct a family of differentially 4-uniform involutions with optimal algebraic degree and high nonlinearity. It is also shown with the help of computer that such involutions which are CCZ-inequivalent to the known differentially 4-uniform permutations in small number of even dimensions are constructed. Furthermore, the number of CCZ-inequivalent classes of our involutions over F 2 n increases exponentially when n increases. [ABSTRACT FROM AUTHOR]

We introduce a Functional Encryption (FE) scheme for the class of languages accepted by extended automata. In an extended automaton, n Deterministic Finite Automata (DFA), each with at most q states, are linked in a cascade such that in each transition the i -th DFA performs its own transition and outputs an input symbol for DFA number i + 1 mod n . Our scheme encrypts a message m with a word w and the resulting ciphertext can be decrypted only by a key that is associated with an automaton that accepts w . Our scheme has key size O ( n q 2 ) , while the ciphertext length and encryption and decryption times are O ( n | w | ) . Our scheme is significantly more efficient than previous proposals, e.g. Waters (Crypto'12), for interesting applications of FE for regular languages such as accepting a word in a regular language only if it is accompanied by a standard public key signature on that word. [ABSTRACT FROM AUTHOR]

Connected health is a technology that associates medical devices, security devices and communication technologies. It enables patients to be monitored and treated remotely from their home. Patients’ data and medical records within a connected health system should be securely stored and transmitted for further analysis and diagnosis. This paper presents a set of security solutions that can be deployed in a connected health environment, which includes the advanced encryption standard (AES) algorithm and electrocardiogram (ECG) identification system. Efficient System-on-Chip (SoC) implementations for the proposed algorithms have been carried out on the Xilinx ZC702 prototyping board. The Achieved hardware implementation results have shown that the proposed AES and ECG identification based system met the real-time requirements and outperformed existing field programmable gate array (FPGA)-based systems in different key performance metrics such as processing time, hardware resources and power consumption. The proposed systems can process an ECG sample in 10.71 ms and uses only 30% of the available hardware resources with a power consumption of 107 mW . [ABSTRACT FROM AUTHOR]

This work develops a solution for simultaneous physical layer security enhancement and peak-to-average power ratio (PAPR) reduction for orthogonal frequency division multiplexing passive optical network (OFDM-PON) systems. The encryption is carried out within the subcarriers with the help of three-dimensional (3-D) chaotic cat map. Experimental results demonstrate that the OFDM-PON system under the protection of the proposed technique is high sensitive to the secret key, invalid optical network units cannot obtain any useful information from the ciphertext. Besides, the PAPR of the OFDM symbols has also been significantly reduced, and hence the system is more robust against various nonlinear disturbances. [ABSTRACT FROM AUTHOR]

This work proposes a separable reversible data hiding scheme in encrypted images based on pixel value ordering (PVO). After the original image is encrypted using homomorphism encryption by the content owner, the data hider embeds the secret data in encrypted domain. The PVO strategy realizes hiding data in each block. Additive homomorphism guarantees the performance of PVO in encrypted domain is close to that in plain domain. Besides, the homomorphism encryption does not cause data expansion, and the payload can be further improved. With the watermarked encrypted image, if the receiver has only the data hiding key, he can extract the additional data. If the receiver has only the encryption key, he can obtain a decrypted image similar to the original one. If the receiver has both the data hiding key and the encryption key, he can extract the additional data without any error and recover the original image losslessly. [ABSTRACT FROM AUTHOR]

Selective encryption masks all of the content without completely hiding it, as full encryption would do at a cost in encryption delay and increased bandwidth. Many commercial applications of video encryption do not even require selective encryption, because greater utility can be gained from transparent encryption, i.e. allowing prospective viewers to glimpse a reduced quality version of the content as a taster. Our lightweight selective encryption scheme when applied to scalable video coding is well suited to transparent encryption. The paper illustrates the gains in reducing delay and increased distortion arising from a transparent encryption that leaves reduced quality base layer in the clear. Reduced encryption of B-frames is a further step beyond transparent encryption in which the computational overhead reduction is traded against content security and limited distortion. This spectrum of video encryption possibilities is analyzed in this paper, though all of the schemes maintain decoder compatibility and add no bitrate overhead as a result of jointly encoding and encrypting the input video by virtue of carefully selecting the entropy coding parameters that are encrypted. The schemes are suitable both for H.264 and HEVC codecs, though demonstrated in the paper for H.264. Selected Content Adaptive Binary Arithmetic Coding (CABAC) parameters are encrypted by a lightweight Exclusive OR technique, which is chosen for practicality. [ABSTRACT FROM AUTHOR]

An improved scheme of data hiding directly in partially encrypted H.264/AVC videos using CABAC bin-string substitution is proposed. The encryption of Luma prediction modes is designed in addition to residual encryption and motion vector encryption in order to significantly improve the structural deterioration. Both the bin-strings of abs_level and the bin-strings of abs_MVD are exploited for data hiding to provide a higher flexibility for users to select the tradeoff between hiding capacity and video quality. Since the data embedding is done in the encrypted domain, the proposed scheme preserves the confidentiality of video content. With an encrypted video containing the hidden data, the receiver can accomplish data extraction directly in encrypted domain using only the data-hiding key, or obtain a decrypted video similar to the original version using only the cryptographic key. Experimental results have demonstrated that the proposed scheme can achieve better scrambling performance and higher embedding capacity. [ABSTRACT FROM AUTHOR]

In this paper, we propose a novel image cryptosystem, which enables to encrypt the secret images with a smaller-size cover image. Compared with the existing meaningful encryption methods, our cryptosystem has three advantages: (1) non-embedding encryption, i.e., there isn’t any data embedding into the cover image during the encryption process. (2) Our cryptosystem can simultaneously encrypt multiple secret images with one cover image, which greatly improves the security of secret images. (3) Our cryptosystem can accomplish not only the meaningful encryption, but also the meaningless encryption. Thus, people don’t switch encryption methods when meeting different encryption requirements. Our scheme leverages the popular coupled dictionary learning and compressive sensing techniques to accomplish the whole task. Specifically, we use the coupled dictionaries to build connection between the cover image and the secret image, and apply the compressive sensing to decrypt the secret image. To demonstrate the effectiveness of the proposed cryptosystem, a series of experiments are conducted. Experimental results on gray images and colorful RGB images verify its superiority. [ABSTRACT FROM AUTHOR]

Recently, using compressive sensing (CS) as a cryptosystem has drawn attention due to its compressibility and low-complexity during the sampling process. However, when applying such cryptosystem to images, how to protect the privacy of the image while keeping efficiency becomes a challenge. In this paper, we propose a novel image coding scheme that achieves combined compression and encryption under a parallel compressive sensing framework, where both the CS sampling and the CS reconstruction are performed in parallel. In this way, the efficiency can be guaranteed. On the other hand, for security, the resistance to chosen plaintext attack (CPA) is realized with the help of the cooperation between a nonlinear chaotic sensing matrix construction process and a counter mode operation. Furthermore, the defect of energy information leakage in CS-based cryptosystem is also overcome by a diffusion procedure. Experimental and analysis results show the scheme achieves effectiveness, efficiency and high security simultaneously. [ABSTRACT FROM AUTHOR]

In this paper, we propose a novel joint image compression and encryption scheme based on JPEG standard. We realize image encryption at JPEG’s transformation stage. Instead of only using 8 × 8 discrete cosine transform (DCT) for transformation, we generate new orthogonal transforms by embedding an extra rotation angle of π to different stages’ butterflies in 8 × 8 DCT’s flow-graph, and then apply them alternatively for transformation according to a predefined secret key. By carefully controlling the number of rotation angles embedded, the quality control of encrypted images can also be achieved. The encryption algorithm is further enhanced by performing block permutation before the entropy encoding stage. Extensive experiments have been conducted to show the good protection and compression performance of our encryption schemes. Finally, a detailed security analysis is provided to show the encryption schemes’ resistance to various cryptanalysis methods, such as brute-force attack, key sensitivity analysis, replacement attack and statistical attack. [ABSTRACT FROM AUTHOR]

In order to protect data privacy, image with sensitive or private information needs to be encrypted before being outsourced to a cloud service provider. However, this causes difficulties in image retrieval and data management. A privacy-preserving content-based image retrieval method based on orthogonal decomposition is proposed in the paper. The image is divided into two different components, for which encryption and feature extraction are executed separately. As a result, cloud server can extract features from an encrypted image directly and compare them with the features of the queried images, so that users can thus obtain the image. Different from other methods, the proposed method has no special requirements to encryption algorithms, which makes it more universal and can be applied in different scenarios. Experimental results prove that the proposed method can achieve better security and better retrieval performance. [ABSTRACT FROM AUTHOR]

As Cloud Computing becomes prevalent, more and more sensitive information has been outsourced into cloud. A straightforward methodology that can protect data privacy is to encrypt the data before outsourcing. Recently, many searchable encryption schemes have been proposed to allow users to execute keyword-based search over encrypted data. However, it is different for users to exactly find all the interested files from the huge amounts of data by relying solely on keyword-based search. In information retrieval domain, full-text retrieval is an efficient information retrieval technology that allows efficient searches over massive amount of web data. Unfortunately, when applied in the cloud paradigm, full-text retrieval over encrypted cloud data have not been well studied. The full-text retrieval service requires extracting all the words in the contents of documents. The huge scale of index words cannot be efficiently supported by the existing searchable encryption schemes. Moreover, to protect user’s privacy, a privacy-preserved full-text retrieval index is required. These problems make efficient full-text retrieval over a large amount of encrypted cloud data a very challenging task. In this paper, we first establish a set of strict privacy requirements for full-text retrieval in cloud storage systems. To address the challenging problem, we design a Bloom filter based tree index. Our scheme fine-tunes the similarity between the query and encrypted documents by proposing the membership entropies of index words. Our scheme is provably secure through our security analysis. We demonstrate the effectiveness and efficiency of the proposed scheme through extensive experimental evaluation. The experimental results manifest the search operation can be done in 60 milliseconds using an off-the-shelf moderate PC. [ABSTRACT FROM AUTHOR]

• The highlight of proposed key distribution method reflects on the scalable key distribution rate (KDR), not limited key distribution distance, and sufficient security compared to key distribution strategies of QKD, synchronization of chaotic laser, and fiber channel feature extraction. • The scalable KDR reflects on that the KDR can reach a rate of 100Gbit/s at 100% key consistency rate (KCR) without consideration of the balance of KDR and KCR. And, the KDR can be augmented by extending hardware resources of key distribution. • For distribution distance , synchronized chaotic equation systems are innovatively realized by identical hardware equipment, high dimensional hyperchaotic equation, initial value, and micro interference. The synchronization keeping with micro interference of proposed chaotic systems is obtained based on identical quantified fiber BER feature of legal fiber loop. And, all synchronous operation controls to proposed chaotic systems are guaranteed by deterministic rule of algorithm operation, and are not limited by amplifier or fiber length. • The security reflects on that the key distribution strategy is immunized to many possible attacks. • Furthermore, as far as we concerned, there has not the deterministic rule of algorithm operation based key distribution method. In addition, proposed method has economic value attribute to it can be fast applied at scenarios of security access of PON equipment, key provision for experiment, and long haul security optical communication. Security key is necessary for data encryption while transmitting amounts of confidential information. For existing strategies of key distribution, it is the primary challenge that the rate and distance limit, insufficient security, and difficulty of deployment. To solve these problems, we propose an accelerated key distribution method for endogenously secure optical communication by synchronized chaotic system based on BER feature of fiber channel. First, synchronized chaotic equation systems are innovatively realized by identical hardware equipment, chaotic equation, initial value, and micro interference. Then, the synchronization keeping with micro interference of proposed chaotic systems are obtained based on identical BER feature of fiber loop. Innovatively, all synchronous operation controls to proposed chaotic systems are guaranteed by deterministic rule of algorithm operation, and are not limited by amplifier or fiber length. Experimental result demonstrates that proposed chaotic systems are synchronized under long term operation. The key distribution rate (KDR) can reach a rate of 100Gbit/s at 100% key consistency rate. And, the KDR can be augmented by extending hardware resources of key distribution. Simulation is conducted to illustrate the security of chaotic systems by the bifurcation diagram, scatter plot diagram, and initial value sensitive phenomenon. NIST security test suite demonstrates that generated secret key sequences pass the test. Moreover, possible attacks are analysed for the security robustness of proposed scheme. The results illustrate proposed system is a reliable, secure and cost-effective solution for high-speed and long-haul key distribution. [ABSTRACT FROM AUTHOR]

Vehicular ad hoc network (VANET) is an increasing important paradigm, which not only provides safety enhancement but also improves roadway system efficiency. However, the security issues of data confidentiality, and access control over transmitted messages in VANET have remained to be solved. In this paper, we propose a secure and efficient message dissemination scheme (SEMD) with policy enforcement in VANET, and construct an outsourcing decryption of ciphertext-policy attribute-based encryption (CP-ABE) to provide differentiated access control services, which makes the vehicles delegate most of the decryption computation to nearest roadside unit (RSU). Performance evaluation demonstrates its efficiency in terms of computational complexity, space complexity, and decryption time. Security proof shows that it is secure against replayable choosen-ciphertext attacks (RCCA) in the standard model. [ABSTRACT FROM AUTHOR]

Reversible data hiding for encrypted signals with prefect reconstruction of directly decrypted signals is introduced in this paper. Each unit in the original image is separated into three components by energy transfer equation, and each component is encrypted by Paillier homomorphic encryption. Additional bits are concealed into the encrypted image by manipulating the encrypted signals. Finally, the original image can be perfectly recovered when direct decryption is applied. The embedded bits are lossless extracted as well. Optimal visual quality and improved embedding rate are obtained by the proposed approach, since the value of the directly decrypted unit is the same as the original one. Experimental results and comparisons are demonstrated to illustrate the effectiveness and advantages of the proposed method. Moreover, the proposed method can be extended to deal with encoded multimedia, which further enriches the application scenarios. [ABSTRACT FROM AUTHOR]

In this paper, reversible image data hiding in the Paillier cryptosystem is investigated. To transmit additional data in homomorphic encryption domain, two algorithms are proposed for different application scenarios. By exploiting the additive homomorphism, high-capacity data hiding can be accomplished with the first algorithm by conducting value expansion on the encrypted pixel values. But the hidden data can only be extracted after image decryption (i.e., in plain-text domain). With the second algorithm, both of data embedding and extraction can be performed in the encryption domain by exploiting the self-blinding property, while the corresponding plain-text values are unchanged. Compared with the reversible data hiding algorithms designed for encryption with a cipher stream, the proposed ones are more applicable in cloud computing without degrading the security level. Thus the additional data can be losslessly transmitted in the different applications of Paillier cryptosystem. [ABSTRACT FROM AUTHOR]

This paper proposes an improved method of reversible data hiding in encrypted images (RDH-EI). Three parties constitute the proposed system: the image owner, the remote server and the recipient. To preserve privacy, an image owner encrypts the original image using a stream cipher algorithm and uploads the ciphertext to a remote server. On server side, a data-hider is allowed to embed additional message into the encrypted image using a swapping/shifting based algorithm. After downloading the marked encrypted image from the server and implementing the decryption, a recipient can extract the hidden messages and losslessly recover the original image. Experimental results show that the proposed method achieves a larger payload than the related works. Meanwhile, a limitation in the related works that few bits can be embedded into the encrypted medical images is also eliminated in the proposed method. [ABSTRACT FROM AUTHOR]

This paper addresses the problem of unauthorized redistribution of multimedia content by malicious users (pirates). In this method three color channels of the image are considered a 3D space and each component of the image is represented as a point in this 3D space. The distribution side uses a symmetric cipher to encrypt perceptually essential components of the image with the encryption key and then sends the encrypted data via multicast transmission to all users. The encryption involves rotation, and translation of points in 3D color space using quaternion algebra. Each user has a unique decryption key which is different from the encryption key. The differences between the common encryption key and the individual user’s decryption key cause the decrypted image to contain minor changes which are user’s fingerprint. A computer-based simulation was conducted to examine the method’s robustness against noise, compression, and collusion attacks. [ABSTRACT FROM AUTHOR]

The materials which cater to excellent sensitivity, superior contrast, inexpensive and eco-friendly are in urgent need for law enforcement applications. To overcome these barriers, red-emitting BiOCl:Eu3+ (1–9 ​mol %) nanophosphors were prepared by the self-ignited combustion method. The powdered x-ray diffraction profiles were well indexed to a tetragonal phase of BiOCl without any traces of impurities. The 2-dimensional agglomerated irregular flake-like structures without any clear boundaries were clearly revealed. The photoluminescence emission spectra consist of distinct sharp peaks at ∼ 536, 555, 594, 621, 652 and 698 ​nm, which were owing to 5D 1 →7F 1 , 5D 1 →7F 2 , 5D 0 →7F 1 , 5D 0 →7F 2 , 5D 0 →7F 3 and 5D 0 →7F 4 transitions of Eu3+ ions, respectively. A noticeable increment in the photoluminescence emission intensity with an increase of activator Eu3+ concentration up to 5 ​mol % and later it diminished. The dipole-dipole interaction was mainly responsible for observed concentration quenching. The estimated commission international de l'eclairage coordinates are found in orange-red as well as a red region in the diagram, indicating that the emission color can be tuned by varying activator Eu3+ ions concentration. The fingerprints developed using optimized nanophosphor showed distinctive papillary ridge particulars and hence specifies the higher sensitivity without any background hindrance. The aged fingerprints developed on the glass surface retained their ridge characteristics up to level 2 even after being stored for 180 days. The developed anti-counterfeiting labels can only be decoded under ultra-violet 365 ​nm light with clear intense red color. The obtained results clearly demonstrated the effectiveness of the fluorescence nanophosphor for latent fingerprint visualization and data encryption applications. [Display omitted] • Red emitting BiOCl:Eu3+ (1–9 ​mol %) phosphors were prepared by solution combustion route. • A new fluorescence based platform has been setup for visualization of latent fingerprints by powder dusting method. • Developed latent fingerprints shows superior contrast, sensitivity, efficiency, selectivity and negligible background hindrance. • Developed anti-counterfeiting labels can only be decoded under ultra-violet 365 ​nm light. [ABSTRACT FROM AUTHOR]

A novel ROI-based reversible data hiding scheme in encrypted medical images is proposed. Firstly, a content owner partitions an original medical image into the region of interest (ROI) and the region of noninterest (RONI), and then encrypts the image using an encryption key. A data-hider concatenates the least significant bits (LSB) of the encrypted ROI and Electronic Patient Record (EPR), and then embeds the concatenated data into the encrypted image by LSB substitution algorithm. With the encrypted medical image containing the embedded data, the receiver can extract the embedded data with the data-hiding key; if the receiver has the encryption key, a medical image similar to the original image can be obtained by directly decrypting the encrypted medical image; if the receiver has both the data-hiding key and the encryption key, the embedded data can be extracted without any error and ROI can be losslessly recovered after extracting the embedded data. [ABSTRACT FROM AUTHOR]

Issues such as content identification, document and image security, audience measurement, ownership and copyright among others can be settled by the use of digital watermarking. Many recent video watermarking methods show drops in visual quality of the sequences. The present work addresses the aforementioned issue by introducing a robust and imperceptible non-blind color video frame watermarking algorithm. The method divides frames into moving and non-moving parts. The non-moving part of each color channel is processed separately using a block-based watermarking scheme. Blocks with an entropy lower than the average entropy of all blocks are subject to a further process for embedding the watermark image. Finally a watermarked frame is generated by adding moving parts to it. Several signal processing attacks are applied to each watermarked frame in order to perform experiments and are compared with some recent algorithms. Experimental results show that the proposed scheme is imperceptible and robust against common signal processing attacks. [ABSTRACT FROM AUTHOR]

Joint fingerprinting and decryption (JFD) is useful in securing media transmission and distribution in a multicasting environment. Common drawbacks of the existing JFD methods are the transmitted data may leak the content of data, and a subscriber cannot determine if a received image is modified such that tampering attack can be mounted successfully. Here we focus on security and privacy of image multicasting and introduce a new framework called JFDA (joint privacy-preserving fingerprinting, decryption, and authentication). It has several main characteristics, JFDA: (1) accomplishes fingerprinting in the encryption domain to preserve privacy and prevent encrypted data from being tampered without additional hash code/digest, (2) prevents tampering attack on the decrypted data to ensure the fidelity of the fingerprinted data, (3) makes user subscribing to a visual media be an examiner to authenticate the same visual media over the Internet. The effectiveness of the proposed method is confirmed by experimental results. [ABSTRACT FROM AUTHOR]

New multivariable asymmetric public-key encryption schemes based on the NP-complete problem of simultaneous algebraic Riccati equations over finite fields are suggested. We also provide a systematic way to describe any set of quadratic equations over any field, as a set of algebraic Riccati equations. This has the benefit of systematic algebraic crypt-analyzing any encryption scheme based on quadratic equations, to any possible vulnerable hidden structure, in view of the fact that the set of all solutions to any given single algebraic Riccati equation is fully described in terms of all the T -invariant subspaces of some restricted dimension, where T is the matrix of coefficients of the related algebraic Riccati equation. [ABSTRACT FROM AUTHOR]

Recently, a novel scheme to hide data into encrypted H.264/AVC videos using code-word substitution has been proposed by Xu et al. However, the statistical analysis of CAVLC code-words demonstrate that Xu et al.’s work does not fully exploit redundancy existing in CAVLC code-word for data embedding. In this paper, an improved version of Xu et al.’s data hiding method in encrypted H.264/AVC videos is proposed. Specifically, when suffixLength is equal to 1, data embedding is performed by paired code-word substitution. When suffixLength is greater than 2, not the single code-word substitution but the multiple-based notational system is adopted for data embedding. Experimental results have demonstrated that the improved method is indeed capable of providing a larger embedding capacity in comparison with Xu et al.’s method. Moreover, both encryption and data embedding can be accomplished without affecting the coding efficiency of H.264/AVC by keeping exactly the same bitrate. [ABSTRACT FROM AUTHOR]

Consider a scenario in which parties use a public-key encryption scheme and a signature scheme with a single public key/private key pair—so the private key sk is used for both signing and decrypting. Such a simultaneous use of a key is in general considered poor cryptographic practice, but from an efficiency point of view looks attractive. We offer security notions to analyze such violations of key separation. For both the identity- and the non-identity-based setting, we show that—although being insecure in general—for schemes of interest the resulting combined scheme can offer strong security guarantees. [ABSTRACT FROM AUTHOR]

To enjoy the advantages of cloud service while preserving security and privacy, huge data are increasingly outsourced to cloud in encrypted form. Unfortunately, most conventional encryption schemes cannot smoothly support encrypted data analysis and processing. As a significant topic, several schemes have been recently proposed to securely compute k -nearest neighbors ( k -NN) on encrypted data being outsourced to cloud server (CS). However, most existing k -NN search methods assume query users (QUs) are fully-trusted and know the key of data owner (DO) to encrypt/decrypt outsourced database. It is not realistic in many situations. In this paper, we propose a new secure k -NN query scheme on encrypted cloud data. Our approach simultaneously achieves: (1) data privacy against CS: the encrypted database can resist potential attacks of CS, (2) key confidentiality against QUs: to avoid the problems caused by key-sharing, QUs cannot learn DO’s key, (3) query privacy against CS and DO: the privacy of query points is preserved as well, (4) query controllability : QUs cannot launch a feasible k -NN query for any new point without approval of DO. We provide theoretical guarantees for security and privacy properties, and show the efficiency of our scheme through extensive experiments. [ABSTRACT FROM AUTHOR]

Data deduplication is an attractive technology to reduce storage space for increasing vast amount of duplicated and redundant data. In a cloud storage system with data deduplication, duplicate copies of data will be eliminated and only one copy will be kept in the storage. To protect the confidentiality of sensitive data while supporting deduplication, the convergent encryption technique has been proposed to encrypt the data before outsourcing. However, the issue of keyword search over encrypted data in deduplication storage system has to be addressed for efficient data utilization. This paper firstly proposes two constructions which support secure keyword search in this scenario. In these constructions, the integrity of the data can be realized by just checking the convergent key, without other traditional integrity auditing mechanisms. Then, two extensions are presented to support fuzzy keyword search and block-level deduplication. Finally, security analysis is given. [ABSTRACT FROM AUTHOR]

As the low complexity of low-dimensional chaotic system and the slow speed of image encryption, this paper proposes a fast encryption algorithm of color image based on four-dimensional chaotic system. Firstly, we propose a new method of designing four-dimensional chaotic system based on the classical equations of three-dimensional chaotic system, to increase the complexity and key space of the encryption algorithm. Secondly, according to the nature of color images’ pixels channel, we design a new pseudo-random sequence generator and reuse the random sequence, to improve the speed of image encryption. Finally, the methods of row-major and column-major are used to diffuse the original image and the cat map with parameter is used to scramble the image pixels, respectively, to achieve the effect of encryption. The results of simulation and security analysis show that the proposed encryption algorithm is of good performance on security, robustness and high encryption speed. [ABSTRACT FROM AUTHOR]

The key benefits of cloud services such as low cost, access flexibility, and mobility have attracted worldwide users to utilize deep learning algorithms for computer vision. These cloud servers are maintained by third parties, where users are always concerned about sharing their confidential data with them. In this paper, we addressed these concerns for by developing SecureDL , a privacy-preserving image recognition model for encrypted data over cloud. The proposed block-based image encryption scheme is well designed to protect image's visual information. The scheme constitutes an order-preserving permutation ordered binary number system and pseudo-random matrices. The proposed method is proved to be secure in a probabilistic viewpoint, and using various cryptographic attacks. Experiments are conducted over several image recognition datasets, and the trade-off analytics between the achieved recognition accuracy and data encryption is well described. SecureDL overcomes the storage and computational overheads that occur with fully-homomorphic and multi-party computation based secure recognition schemes. • The goal of this study is to analyze the trade-off relation between image privacy and recognition. • Order-preserving permutation ordered binary number system and pseudo-random matrices are used to achieve image security. • The proposed method is assessed with encrypted data over a variety of datasets. • Security analysis of the proposed method is established using mathematical proofs and standard tests. [ABSTRACT FROM AUTHOR]

Multivariate cryptography is one of the main candidates to guarantee the security of communication in the presence of quantum computers. While there exist a large number of secure and efficient multivariate signature schemes, the number of practical multivariate encryption schemes is somewhat limited. In this paper we present our results on creating a new multivariate encryption scheme, which is an extension of the original SimpleMatrix encryption scheme of PQCrypto 2013. Our scheme allows fast en- and decryption and resists all known attacks against multivariate cryptosystems. Furthermore, we present a new idea to solve the decryption failure problem of the original SimpleMatrix encryption scheme. [ABSTRACT FROM AUTHOR]