Dynamic Encryption Research Articles

Database Padding for Dynamic Symmetric Searchable Encryption

Dynamic symmetric searchable encryption (DSSE) that enables the search and update of encrypted databases outsourced to cloud servers has recently received widespread attention for leakage-abuse attacks against DSSE. In this paper, we propose a dynamic database padding method to mitigate the threat of data leakage during the update operation of outsourcing data. First, we introduce an outlier detection technology where bogus files are generated for padding according to the outlier factors, hiding the document information currently matching search keywords. Furthermore, we design a new index structure suitable for the padded database using the bitmap index to simplify the update operation of the encrypted index. Finally, we present an application scenario of the padding method and realize a forward and backward privacy DSSE scheme (named PDB-DSSE). The security analysis and simulation results show that our dynamic padding algorithm is suitable for DSSE scheme and PDB-DSSE scheme maintains the security and efficiency of the retrieval and update of the DSSE scheme.

SECURE MEDICAL IMAGE ENCRYPTION FOR REMOTE VIRTUAL DOCTOR SYSTEM BASED ON H-IOT APPLICATIONS OVER 5G NETWORK: A COMPARISON STUDY

Abstract. Recent years have seen a new amalgamation between Remote virtual doctor systems and healthcare IoT applications which plays a crucial role in enhancing patient’s healthcare life. The Remote VDS connected with smart Healthcare devices through the wireless network to be accessible anytime and anywhere is anticipated to treat rapidly valuable and confidential data such as personal medical images. Therefore, quick medical image encryption is an essential task in healthcare topic. Some medical image encryption research like the Scan methodology proposed for Remote VDS suffers from a long computational time. Then, the patient will confront difficulty on treatment availability in real-time and especially for critical situations. To overcome this problem, in this work, three medical image encryption methods are compared, (1) A Lightweight Encryption Technique to Enhance Medical Image Security on Internet of Medical Things Applications, (2) A new chaotic map with dynamic analysis and encryption application on the Internet of Health Things, and (3) Robust medical image encryption based on DNA chaos method. The comparison results have proven that the new chaotic map with a dynamic analysis scheme has high-security analysis and performances with low computational time compared to other methods. That makes it a good candidate for the H-IOT-RVDS environment connecting over 5G technology like a cellular network to enable connectivity between nodes.

A Secure Searchable Encryption Framework for Privacy-Critical Cloud Storage Services

Searchable encryption has received a significant attention from the research community with various constructions being proposed, each achieving asymptotically optimal complexity for specific metrics (e.g., search, update). Despite their elegance, the recent attacks and deployment efforts have shown that the optimal asymptotic complexity might not always imply practical performance, especially if the application demands a high privacy. In this article, we introduce a novel Dynamic Searchable Symmetric Encryption (DSSE) framework called Incidence Matrix (IM)-DSSE, which achieves a high level of privacy, efficient search/update, and low client storage with actual deployments on real cloud settings. We harness an incidence matrix along with two hash tables to create an encrypted index, on which both search and update operations can be performed effectively with minimal information leakage. This simple set of data structures surprisingly offers a high level of DSSE security while achieving practical performance. Specifically, IM-DSSE achieves forward-privacy, backward-privacy and size-obliviousness simultaneously. We also create several DSSE variants, each offering different trade-offs that are suitable for different cloud applications and infrastructures. We fully implemented our framework and evaluated its performance on a real cloud system (Amazon EC2). We have released IM-DSSE as an open-source library for wide development and adaptation.

DMSE: Dynamic Multi-keyword Search Encryption based on inverted index

With the popularity of cloud storage, increasing people are willing to upload their files to cloud services. They will encrypt these files before uploading to protect the privacy of files. However, encryption makes effective search very difficult and inefficient. In this paper, we design a dynamic multi-keyword searchable encryption scheme on the encrypted cloud files, called DMSE. Firstly, the outsourced files in DMSE are pre-classified and preprocessed according to their privacy to achieve classified search. Secondly, based on the inverted index, DMSE realizes multiple keywords search, which protects the privacy of outsourced files and users and greatly improves the search efficiency. In addition, our DMSE extends the inverted index to the multi-DO/multi-DU scenario, which is the distinguishable difference between DMSE and other existing multi-keyword search schemes. Thirdly, our DMSE can further support the update of keywords to cope with the mismatch dilemma between the first extracted keywords and outsourced files, thus improving the practicality of DMSE scheme. Finally, comprehensive performance evaluation shows our DMSE scheme is effective and feasible in practical application.

Polyacrylamide-Based Binary Luminescent Copolymer Materials Exhibit Color-Tunable and Efficient Long-Lived Room Temperature Phosphorescence.

Polymer-based pure organic room temperature phosphorescence (RTP) materials have garnered considerable interest, among which RTP systems with prolonged lifetimes and tunable emission colors are promising for applications in sensing, flexible electronics, bioassay, anti-counterfeiting, and data encryption. Herein, facile doping method is reported based on two types of copolymers with benzene/biphenyl-based light-emitting cores as their side chains, whereby the two copolymers are robustly crosslinked via noncovalent interactions including hydrogen bonding and halogen bonding that occur between the light-emitting cores and polyacrylamide backbones. Persistent RTP emission with prolonged lifetime up to 1.9 s and phosphorescence quantum yield as high as 40.1% are obtained in single copolymers, attributed to the conformation restriction of phosphorescent dyes originating from the rigid microenvironment. Furthermore, multicolor phosphorescence signals are observed in the doped binary luminescent copolymer systems that can be effectively regulated by the feed ratio of luminescent cores and irradiation wavelengths. Possible mechanisms for this efficient and long-lived color-tunable RTP system are discussed on the basis of the experimental data and theoretical calculations. In addition, it is also demonstrated that the color-tunable RTP emission of the doped copolymer systems under ambient conditions allows for further exploitation in the application of dynamic information encryption.

Perovskite Nanocrystals with Tunable Fluorescent Intensity during Anion Exchange for Dynamic Optical Encryption.

Perovskite nanocrystals (PNCs) have demonstrated their potential use in many applications such as optical encryption because of their excellent optical properties. However, the optical encryption using PNCs is mainly based on the formation of static patterns with luminescence on/off switching. In this work, we demonstrated that the capping ligands play an important role in tuning the luminescence intensity of the PNCs during ion exchange. The surfactant, oleylamine (OAm), is essential in shifting the luminescence color of the PNCs from green to yellow during the ion exchange. In the absence of OAm, the luminescence in the green and yellow regions is quenched during the ion exchange and the luminescence is recovered in the red region by adding trioctylphosphine (TOP) into the ion-exchange solution. On the basis of these findings, we proposed a dynamic optical encryption strategy using PNCs with different capping ligands by tuning the luminescence intensity. The encoded message is hidden in the green pattern at the beginning, shown during the ion exchange, and erased when the pattern is completely converted from a green color to a red color after the ion exchange ends. This dynamic encryption strategy enhances the security level and is compatible with human eye-perceivable patterns and binary coding algorithms.

Plaintext-Related Dynamic Key Chaotic Image Encryption Algorithm.

To address the problems of the high complexity and low security of the existing image encryption algorithms, this paper proposes a dynamic key chaotic image encryption algorithm with low complexity and high security associated with plaintext. Firstly, the RGB components of the color image are read, and the RGB components are normalized to obtain the key that is closely related to the plaintext, and then the Arnold transform is used to stretch and fold the RGB components of the color image to change the position of the pixel points in space, so as to destroy the correlation between the adjacent pixel points of the image. Next, the generated sequences are independently encrypted with the Arnold-transformed RGB matrix. Finally, the three encrypted images are combined to obtain the final encrypted image. Since the key acquisition of this encryption algorithm is related to the plaintext, it is possible to achieve one key per image, so the key acquisition is dynamic. This encryption algorithm introduces chaotic mapping, so that the key space size is . The key acquisition is closely related to the plaintext, which makes the ciphertext more random and resistant to differential attacks, and ensures that the ciphertext is more secure after encryption. The experiments show that the algorithm can encrypt the image effectively and can resist attack on the encrypted image.

BRISK: Dynamic Encryption Based Cipher for Long Term Security.

Several emerging areas like the Internet of Things, sensor networks, healthcare and distributed networks feature resource-constrained devices that share secure and privacy-preserving data to accomplish some goal. The majority of standard cryptographic algorithms do not fit with these constrained devices due to heavy cryptographic components. In this paper, a new block cipher, BRISK, is proposed with a block size of 32-bit. The cipher design is straightforward due to simple round operations, and these operations can be efficiently run in hardware and suitable for software. Another major concept used with this cipher is dynamism during encryption for each session; that is, instead of using the same encryption algorithm, participants use different ciphers for each session. Professor Lars R. Knudsen initially proposed dynamic encryption in 2015, where the sender picks a cipher from a large pool of ciphers to encrypt the data and send it along with the encrypted message. The receiver does not know about the encryption technique used before receiving the cipher along with the message. However, in the proposed algorithm, instead of choosing a new cipher, the process uses the same cipher for each session, but varies the cipher specifications from a given small pool, e.g., the number of rounds, cipher components, etc. Therefore, the dynamism concept is used here in a different way.

A novel image encryption algorithm using PWLCM map-based CML chaotic system and dynamic DNA encryption

A novel image encryption algorithm using PWLCM map-based CML chaotic system and dynamic DNA encryption

A Comparative Study of Traffic Classification Techniques for Smart City Networks.

Smart city networks involve many applications that impose specific Quality of Service (QoS) requirements, thus representing a challenging scenario for network management. Solutions aiming to guarantee QoS support have not been deployed in large-scale networks. Traffic classification is a mechanism used to manage different aspects, including QoS requirements. However, conventional traffic classification methods, such as the port-based method, are inefficient because of their inability to handle dynamic port allocation and encryption. Traffic classification using machine learning has gained research interest as an alternative method to achieve high performance. In fact, machine learning embeds intelligence into network functions, thus improving network management. In this study, we apply machine learning algorithms to predict network traffic classification. We apply four supervised learning algorithms: support vector machine, random forest, k-nearest neighbors, and decision tree. We also apply a port-based method of traffic classification based on applications’ popular assigned port numbers. Then, we compare the results of this method to those obtained from the machine learning algorithms. The evaluation results indicate that the decision tree algorithm provides the highest average accuracy among the evaluated algorithms, at 99.18%. Moreover, network traffic classification using machine learning provides more accurate results and higher performance than the port-based method.

A blockchain-based dynamic searchable symmetric encryption scheme under multiple clouds

A blockchain-based dynamic searchable symmetric encryption scheme under multiple clouds

Key Management Scheme for Secure Channel Establishment in Fog Computing

Fog computing is a promising extension of cloud computing, and enables computing directly at the edge of the network. Due to the decentralized and distributed nature of fog nodes, secure communication channels have to be supported in fog computing, which are generally realized through secure keys. Key management schemes are usually employed to generate, distribute and maintain the secret keys. In this paper, we propose a key management scheme called dynamic contributory broadcast encryption (DConBE) for secure channel establishment in fog computing. It allows a group of fog nodes that want to establish a fog system to negotiate a public encryption key and each node’s decryption key in one round without a trusted dealer. Any end user may encrypt messages under the public encryption key with short ciphertexts to any subset of the fog nodes in the system. Only selected fog nodes in the system can decrypt the encrypted messages using their respective decryption key. Our new key management scheme also achieves the properties of fog node dynamics, fully collusion-resistant and stateless.

Code Division Multiplexing Inspired Dynamic Metasurface Holography

AbstractMetasurface holography is attracting increasing attention owing to its numerous advantages over conventional holography techniques, such as precise control of phase profiles, compact sizes, and multiple information channels via a single optical element. Metasurfaces provide a flexible platform for incorporating various multiplexing techniques. Inspired by code division multiplexing (CDM), which is widely employed in networking and wireless digital communications, metasurface holography for generating dynamic holographic images controlled by both the patterned beam profiles and polarization states is designed and realized in this study. Specifically, two orthogonal polarization states and 16 code bases of light illumination are combined to generate 32 independent channels. Only the correct code reference can decode the target image for a specific channel, providing encryption for information transportation. Meanwhile, the demonstrated metasurface holography with CDM can realize active modulation via a digital micromirror device. The proposed metasurface can be utilized to achieve dynamic information display, data storage, optical encryption, and other applications in optics.

Forward and backward secure keyword search with flexible keyword shielding

Dynamic Searchable Symmetric Encryption (DSSE) has gained increasing popularity as it enables users to perform both file updates and ciphertext retrieval over encrypted data. However, existing DSSE schemes still lead to privacy leakage (e.g., forward and backward privacy) in the dynamic setting. Some forward and backward secure DSSE schemes have been proposed, but still cannot support the keyword shielding flexibly. To solve this challenging issue, we propose a Forward and Backward Authorized Keyword Search (FB-AKS) scheme with recoverable keyword shielding by using trapdoor permutations and puncturable encryption in this paper. Compared with existing forward and backward private schemes, FB-AKS achieves keyword authorization flexibly (e.g., keyword shielding, keyword un-shielding). The formal security analysis proves that FB-AKS achieves forward and backward security. And extensive experiments demonstrate that FB-AKS has less computation and storage overheads.

Fair multi-owner search over encrypted data with forward and backward privacy in cloud-assisted Internet of Things

The trend towards the Internet of Things (IoT) technology promises the growth of home and organizational automation in the world. Due to the large amount of IoT data stored in the semi-trust cloud server, the IoT is vulnerable to cyberattacks. Therefore, the privacy violation of outsourced data is an obstacle to efficient IoT data storage. Searchable encryption is a promising solution for secure storage and selective data retrieval. However, achieving desired privacy, performance, and attributes such as dynamics, access control, scalability, and fair arbitration is still a challenge in searchable encryption schemes. In this paper, we propose a fair and dynamic multi-owner searchable encryption scheme wherein dynamics does not leak the sensitive information. In the proposed scheme, the verifiability and fair arbitration, respectively, prevent the malicious cloud servers and malicious users from having any motivation to disrupt the accuracy of the exchanged data. Generating a single trapdoor corresponding to the conjunctive keyword query, a client can search over all documents stored in the cloud, the owner of which has allowed the client to access. We also prove that our scheme is secure against the keyword guessing attack in the standard model. Finally, evaluating the performance of the proposed scheme on a real dataset, we demonstrate its efficiency as well.

Multimode dynamic luminescent switching of lead halide hybrids for anti-counterfeiting and encryption

Two zero-dimensional inorganic–organic lead halide hybrids, namely [PP14]2[PbBr4] (1, PP14 = N-butyl-N-methylpiperidinium) and [PP14]9[PbBr4]2[Pb3Br11] (2) were synthesized in the ionic liquid (IL) of [PP14]Br. Reversible structure and luminescence transformations between 1 and IL@2 were observed under specific conditions. The dynamic transformation processes were involved with the extraction/insertion of IL, which is demonstrated through in-situ powder X-ray diffraction, differential scanning calorimetry, single crystal X-ray diffraction, in-situ steady-state photoluminescence, etc. The potential application of title compounds as fluorescent security inks in dynamic anti-counterfeiting and encryption was developed as well. The mechanism of multimode-responsive luminescent change was studied, which not only provides deep insight into the photoluminescence switching but also offers an effective strategy for the design of novel stimuli-responsive materials.

Efficient and dynamic verifiable multi-keyword searchable symmetric encryption with full security

Increasing the popularity of cloud computing raises the importance of efforts to improve the services of this paradigm. Searching over encrypted data is a requirement for cloud storage to provide, in addition to privacy-preserving, convenient and low-cost access to some of the outsourced data. Security and functionality along with efficiency are important characteristics of searchable encryption schemes that improve them make this schemes more applicable to the real world. There are proposed structures for symmetric searchable encryption (SSE) in this paper, by adding functionalities to randomized SSE schemes, to provide a optimal scheme. We design a rFSMSE scheme that allows searching by multiple keywords. This scheme is fully secure and its search time complexity is logarithmic. Then we upgrad this scheme to the verifiable rFSMSE scheme called rFSVMSE, without increasing the complexity of search time, storage, and communication. We demonstrate that the proposed schemes are upgradable to dynamic ones. Simulations show the time taken to search for multi-keywords in the rFSMSE and rFSVMSE schemes is less than that in the previous randomized SSE.

Attribute-Based Privacy-Preserving Data Sharing for Dynamic Groups in Cloud Computing

Cloud computing is recognized as an alternative to traditional information technology due to its intrinsic resource sharing and low maintenance characteristics. Cloud computing provides an economical and efficient solution for sharing group resource among cloud users. Unfortunately, when sharing the data in a group while preserving data, identity privacy is still a challenging issue due to frequent change in membership. In overcome this problem, a secure data sharing scheme for dynamic groups is proposed so that any user within a group can share the data in a secure manner by leveraging both the group signature and dynamic broadcast encryption techniques. It should enable any cloud user to anonymously share data with others within the group and support efficient member revocation. The storage overhead and encryption computation cost are dependent on the number of revoked users.

Privacy-preserving Dynamic Symmetric Searchable Encryption with Controllable Leakage

Searchable Encryption (SE) is a technique that allows Cloud Service Providers to search over encrypted datasets without learning the content of queries and records. In recent years, many SE schemes have been proposed to protect outsourced data. However, most of them leak sensitive information, from which attackers could still infer the content of queries and records by mounting leakage-based inference attacks, such as the count attack and file-injection attack . In this work, first we define the leakage in searchable encrypted databases and analyse how the leakage is leveraged in existing leakage-based attacks. Second, we propose a <underline>P</underline>rivacy-preserving <underline>M</underline>ulti-<underline>c</underline>loud based dynamic symmetric SE scheme for relational <underline>D</underline>ata<underline>b</underline>ase ( P-McDb ). P-McDb has minimal leakage, which not only ensures confidentiality of queries and records but also protects the search, intersection, and size patterns. Moreover, P-McDb ensures both forward and backward privacy of the database. Thus, P-McDb could resist existing leakage-based attacks, e.g., active file/record-injection attacks. We give security definition and analysis to show how P-McDb hides the aforementioned patterns. Finally, we implemented a prototype of P-McDb and tested it using the TPC-H benchmark dataset. Our evaluation results show that users can get the required records in 2.16 s when searching over 4.1 million records.

Physical Layer Dynamic Key Encryption in OFDM-PON System Based on Cellular Neural Network

In this paper, we propose a dynamic key technique based on Cellular Neural Network (CNN) for security improvement in the orthogonal frequency division multiplexing passive optical network (OFDM-PON). To enhance the encryption scheme security, a six-dimensional CNN hyperchaotic system is employed to encrypt the data. And, the keys are divided into the dynamic and static. The dynamic key is randomly extracted from a key set by incorporating the random feature of the input data. Then, the chaotic sequence generated by the dynamic key is served as the synchronous sequence for encryption. Moreover, the chaotic sequences generated by the static keys are used to resist the chosen-plaintext attacks (CPAs) and scramble the phase of QAM symbols on the frequency domain. With these processing techniques, the multi-fold data encryption can create a key space of ~10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">315</sup> to protect against the exhaustive trial. The transmission of 10-Gb/s encrypted 16-QAM-based OFDM signal is demonstrated over 20-km single mode fiber (SMF) by experiment. The results show that our proposed scheme can provide excellent confidentiality of data transmission against the CPAs and brute-force attack.