Plaintext Attack Research Articles

Advanced medical image encryption techniques using the fractional-order Halvorsen circulant systems: dynamics, control, synchronization and security applications

In this paper, we describe the Halvorsen circulant system (HCS) with a fractional-order Caputo derivative and its qualitative properties. The numerical solution of the fractional order Halvorsen circulant system (FO-HCS) is proposed based on the Adomian decomposition method (ADM). The ADM method is used to solve fractional-order systems. Then, dynamics is analyzed using different methods including Lyapunov exponents, bifurcation diagrams, complexity, and phase diagrams. This paper also investigates the stabilization and synchronization of identical FO-HCS, and stability theory proves adaptive feedback control and synchronization. In addition, using the fractional-order system’s remarkable properties to develop the image encryption technique using the extended fractional sequences. The proposed method uses a keystream generator for high security based on the enhanced fractional Halvorsen circulant chaotic behavior. The simulation results confirm that it can resist various attacks, including statistical analysis, differential attacks, brute-force attacks, known plaintext attacks, and chosen plaintext attacks, with high security, and low computational complexity. Finally, the results of the simulation and its performance prove that it's effective and secure in image data.

A dynamic data access control scheme for hierarchical structures in big data

Ciphertext-Policy Attribute-Based Encryption (CP-ABE) is a promising solution to address the issues of data leakage and sharing in big data. When multiple files are shared, they often have hierarchical access relationships. However, existing hierarchical data CP-ABE schemes can only support simple hierarchical access structures. The limitation arises, necessitating the generation of multiple access structures to meet hierarchical access requirements, resulting in the wastage of computational and storage resources. Therefore, in this paper, we carefully design a dynamic hierarchy access control that allows its level nodes to flexibly participate in the decryption of other nodes, enabling the realization of complex hierarchical data relationships. Building upon this, we construct the Attribute-based Dynamic Hierarchical data Access Control (ADHAC) scheme, achieving efficient and dynamic access control for multiple datasets. Subsequently, we apply our scheme in distributed computing, which enables efficient access control for individuals and institutions over multiple data sets and fine-grained computation. Security analysis indicates that our scheme can resist chosen plaintext attack (CPA). Both theoretical and experimental analyses demonstrate that our scheme has impressive advantages in terms of computational efficiency and storage costs compared to existing schemes.

Attribute-Based Data Sharing Scheme Using Blockchain for 6G-Enabled VANETs

The advent of 6G communications technology will bring about a transition from the “Internet of Everything” to the “Intelligent Connection of Everything”. 6G-enabled vehicular ad hoc networks (VANETs) will enjoy lower latency, higher speed, and greater capacity network services. Nevertheless, achieving secure data sharing will be an even tougher challenge. Given this, we propose an attribute-based data sharing scheme with blockchain for 6G-enabled VANETs. First, we propose an efficient multi-tree-based user revocation mechanism. With the Chinese remainder theorem, our mechanism supports user batch revocation and batch joining. Second, we achieve distributed data storage by utilizing the blockchain and smart contracts. To solve the problem of insufficient storage capacity on the blockchain, we adopt a combination of on-chain and off-chain storage. Third, to reduce the computation burden on users, our proposal supports online/offline encryption and verifiable outsourced decryption. Meanwhile, our mechanism supports policy hiding, data revocation, and cross-domain data sharing. The proposed scheme is proven to satisfy the indistinguishability under chosen plaintext attack (IND-CPA) in the standard model. Theoretical analysis shows that our mechanism outperforms existing schemes in functionality and security. Simulation experiments show that our proposal is efficient and suitable for 6G-enabled VANETs.

Data Transmission Security on Cloud Computing using Algorithm

Cloud computing enables businesses to efficiently store vast amounts of data in the cloud, which can be accessed seamlessly over the Internet without hardware compatibility constraints. However, the transmission of data over the Internet is susceptible to various security threats such as man-in-the-middle attacks, known plaintext attacks, chosen ciphertext attacks, related-key attacks, and pollution attacks. Uploading data to a single cloud service may heighten the risk of compromising confidential information. Prior research has explored several cryptography techniques like SA-EDS, RFDA, and EST to secure data storage across multiple cloud platforms. However, these existing methods exhibit vulnerabilities to various attacks. This article focuses on addressing data security challenges in multi-cloud environments and proposes an advanced approach called Proficient Security over Distributed Storage. PSDS has undergone rigorous testing against multiple attacks, demonstrating its resilience against related-key attacks, pollution attacks, chosen ciphertext attacks, and known plaintext attacks. Additionally, PSDS exhibits reduced computational time compared to existing encryption methods such as STTN and RFD.

Image encryption scheme based on improved four-dimensional chaotic system and evolutionary operators

To enhance the security of image data transmission, and address the weaknesses of existing image encryption schemes based on chaotic systems, particularly concerning resistance to differential attacks and the unstable performance of chaotic systems, this article introduces an improved four-dimensional chaotic system and integrates evolutionary operators to propose an image encryption scheme. Firstly, a method for generating pseudo-random sequences associated with the plaintext is designed. The change rate of the ciphertext pixel value exceeds 0.9967 after a slight modification of the plaintext pixel value, significantly improving the plaintext sensitivity and the scheme's ability to resist selected plaintext attacks. Secondly, an individual rearrangement operation is introduced to achieve bit-level scrambling, and pixel-level scrambling is achieved by selection strategy. Subsequently, crossover and mutation operations are incorporated into image encryption. To reflect the randomness of the pairing, we adopt the pseudo-random sequence generated by the chaotic system to control the crossover and mutation operators, and a diffusion operation is performed on selected pixel pairs. Finally, ciphertext feedback is applied. Experimental results and performance analysis demonstrate that the proposed scheme not only enhances the security of encrypted images but also effectively resists noise and cropping attacks. This method effectively meets the high-security requirements of images in network transmission and provides new ideas for further research in the field of image encryption.

Multiple-image encryption scheme based on a new 2D hyperchaotic map with blurred pixels

It is known that chaotic, especially hyperchaotic system can be suitable for the application in image encryption owing to itself characteristics. While currently, certain improved chaotic or hyperchaotic systems are confronted with the security issue of encryption due to their less complex dynamical behaviors. To address the problem well, we introduce a novel two-dimensional (2D) crossed hyperchaotic map which is based on the logistic map and the infinite collapse map. The analysis of phase diagram and Lyapunov exponential spectrum demonstrate that the given system can exhibit extensive hyperchaotic behavior and good traversal properties. Moreover, the growing use of digital images has prompted demand for multi-image encryption scheme. For this reason, based on the given 2D crossed hyperchaotic map, a multiple image encryption (MIE) scheme that employs a cross-plane with the operation of simultaneous permutation and diffusion to modify the values of its positions and pixels across multiple images is proposed. A pixel blur preprocessing technique is introduced such that the efficiency of key calculation and the speed and safety of information encryption are greatly improved. Eventually, some simulation examples and security analysis reveal that the put forward encryption scheme is able to keep out kinds of attacks such as the selective plaintext attacks and data loss.

Enhancing cryptographic robustness with dual key chaining

In this paper, we introduce an advanced mode of operation for block ciphers, named Dual Key Chaining Mode (DKC), aimed at bolstering cryptographic security for safeguarding sensitive information. Building upon the foundations laid by established modes while adhering to guidelines set by the National Institute of Standards and Technology (NIST), DKC innovates through a dual-key mechanism and the generation of highly unpredictable values. This novel approach markedly enhances security, particularly against chosen plaintext attacks, a common vulnerability in traditional modes. Through rigorous mathematical analysis, we demonstrate DKC’s superiority, proving its indistinguishability under chosen plaintext attacks (IND-CPA) and showing that an adversary cannot practically distinguish DKC-encrypted ciphertexts from those produced by a random permutation. Our security proof employs a structured approach, contrasting DKC with conventional modes to highlight its robust defense mechanisms and its capacity to mitigate error propagation, reduce chain dependency, and resist pattern recognition attacks. The DKC mode not only surpasses existing standards in cryptographic security but also offers significant improvements in efficiency and security complexity, making it particularly suited for environments demanding stringent data protection. This study’s findings underscore DKC’s potential as a leading candidate for securing communication channels, financial transactions, and cloud storage services against an array of cryptographic attacks.

On the security of JPEG image encryption with RS pairs permutation

Recently, a JPEG encryption scheme with RS (run/size) pairs multi-permutation and block permutation has been proposed, which mainly improves security by extracting the expected number of RS pairs for global permutations that need overflow processing. However, it still has the risk of information leakage under the chosen plaintext attack. This is because the limited embedding capacity in overflow processing makes the overflow blocks (OBs) less. On the one hand, a few OBs make the sketch generated by non-zero coefficients count after RS pair multi-permutation visually indistinguishable from the original sketch. On the other hand, a few OBs limit the number of extracted RS pairs that can participate in global permutation, so there are many partially extracted blocks (PEBs) containing unextracted RS pairs. More PEBs make the accuracy of the estimated block permutation sequence high, because the unique plaintext block can be constructed as long as there is an unextracted RS pair in an encrypted block. Simulation results show that the correct ratio of block permutation sequence is not less than 60 %. The highest and average PSNRs between the attacked sketch and the original one reach up to 47.07 dB and 27.42 dB, respectively.

Revocable and verifiable weighted attribute-based encryption with collaborative access for electronic health record in cloud

The encryption of user data is crucial when employing electronic health record services to guarantee the security of the data stored on cloud servers. Attribute-based encryption (ABE) scheme is considered a powerful encryption technique that offers flexible and fine-grained access control capabilities. Further, the multi-user collaborative access ABE scheme additionally supports users to acquire access authorization through collaborative works. However, the existing multi-user collaborative access ABE schemes do not consider the different weights of collaboration users. Therefore, using these schemes for weighted multi-user collaborative access results in redundant attributes, which inevitably reduces the efficiency of the ABE scheme. This paper proposes a revocable and verifiable weighted attribute-based encryption with collaborative access scheme (RVWABE-CA), which can provide efficient weighted multi-user collaborative access, user revocation, and data integrity verification, as the fundamental cornerstone for establishing a robust framework to facilitate secure sharing of electronic health records in a public cloud environment. In detail, this scheme employs a novel weighted access tree to eliminate redundant attributes, utilizes encryption version information to control user revocation, and establishes Merkle Hash Tree for data integrity verification. We prove that our scheme is resistant against chosen plaintext attack. The experimental results demonstrate that our scheme has significant computational efficiency advantages compared to related works, without increasing storage or communication overhead. Therefore, the RVWABE-CA scheme can provide an efficient and flexible weighted collaborative access control and user revocation mechanism as well as data integrity verification for electronic health record systems.

FogSec: A secure and effective mutual authentication scheme for fog computing

SummaryAs opposed to cloud servers, fog servers, and fog users may be malicious, so developing a mutual identity‐preserving authentication mechanism between them is a crucial and difficult problem in fog computing. Such a technique must conceal the user's true identity from the adversary; otherwise, the adversary will be able to determine which fog user and fog server are in communication. This article suggests a secure and reliable anonymous mutual authentication system for use at the network's edge between fog users and fog servers. With the aid of the registration authority (RA) in our system, they can verify one another and decide on a new session key that will be used to encrypt messages throughout the session. Fog users don't need to re‐register with RA to wander freely over the network and authenticate to any fog server that is within their range. The proposed technique only needs a small number of symmetric encryption/decryption and one‐way hash functions, making it easy to implement for fog‐user devices with limited resources. The new scheme's performance is evaluated in comparison to the existing one, showing that it is more resilient to various types of assaults (such as known plaintext attacks, man‐in‐the‐middle attacks, session hijacking, etc.). The widely used Automated Validation of Internet Security Protocols and Applications tool is used to verify the proposed system. The outcomes demonstrate that our approach can safely withstand different attacks and accomplish the desired outcomes. Additionally, the proposed method is tested in real‐world scenarios with the NS3 simulator.

Exploring the Security Vulnerability in Frequency-Hiding Order-Preserving Encryption

Frequency-hiding order-preserving encryption (FH-OPE) has emerged as an important tool in data security, particularly in cloud computing, because of its unique ability to preserve the order of plaintexts in their corresponding ciphertexts and enable efficient range queries on encrypted data. Despite its strong security model, indistinguishability under frequency analyzing ordered chosen plaintext attack (IND-FA-OCPA), our research identifies a vulnerability in its design, particularly the impact of range queries. In our research, we quantify the frequency of data exposure resulting from these range queries and present potential inference attacks on the FH-OPE scheme. Our findings are substantiated through experiments on real-world datasets, with the goal of measuring the frequency of data exposure resulting from range queries on FH-OPE encrypted databases. These results quantify the level of risk in practical applications of FH-OPE and reveal the potential for additional inference attacks and the urgency of addressing these threats. Consequently, our research highlights the need for a more comprehensive security model that considers the potential risks associated with range queries and underscores the importance of developing new range-query methods that prevent exposing these vulnerabilities.

Square impossible differential attack and security of AES in known plaintext scenario

In this work, we examine the security of the 8-round AES, under the known plaintext attack scenario, a type of cryptographic attack in which an attacker has access to the plaintext and corresponding ciphertext pairs. We present an innovative impossible differential (ID) attack technique, which utilizes a specific ID characteristic, to perform the first known plaintext attack on the 8-round AES with a 256-bit key. Additionally, we propose a new attack methodology, known as the Square Impossible Differential (SID) attack, to enhance the effectiveness of the ID attacks on AES in chosen ciphertext or plaintext scenarios. The SID attack is a combination of a square attack and an ID attack. Our methodology introduces various new approaches, including the key indicator vectors, eliminating the key candidate through the Meet-in-The-Middle technique and mounting the guess and determine attack through the hash tables for the two-round decryption of one column of AES while determining the subkeys constituting the impossible differential characteristic for a given plaintext/ciphertext difference pair. Our approach demonstrates lower computational complexity compared to previous methods, and our analysis shows that the complexities of our known plaintext attack and SID attack are estimated to be 2220 and 2209, respectively.

Multiuser medical image encryption algorithm using phase-only CGH in the gyrator domain.

In this paper, a multiuser medical image encryption algorithm is proposed. The proposed algorithm utilizes polar decomposition, which enables multiuser features in the proposed algorithm. A computer-generated hologram (CGH) improves the security of the proposed algorithm in the gyrator domain. The phase-only CGH-based multiuser algorithm offers advantages such as storing a large amount of information in a compact space, resistance to counterfeiting, and enhanced security. The proposed method is validated with various statistical metrics, such as information entropy, mean squared error, correlation coefficient, histogram, and mesh plots. Results confirm that the proposed algorithm is secure and robust against potential attacks, such as plaintext attacks, iterative attacks, and contamination attacks. The proposed method has a large keyspace, which makes it very difficult to be breached in real-time with existing computational power.

Cryptanalysis of an image encryption scheme based on two-point diffusion strategy and Henon map

In recent year, an image encryption scheme was proposed based on Henon map and two-point diffusion strategy. Two-point diffusion method improved the conventional permutation–diffusion architecture by allowing two cryptographic primitives, i.e. permutation and diffusion intermingling with each other in every single round. In this paper, we show the dynamical degradation of digital Henon map using state-mapping network. By comparing to the exhaustive key search, applying algebraic cryptanalysis and chosen plaintext attack require lower time complexity of computation. The recovery of equivalent keys also reduces the possible numbers of secret keys. The keystream recovery process has been verified using simulations. We also show that the two-point diffusion strategy does not improve the efficiency of the image encryption scheme and some improvement suggestions using parallel computing are given. As a nutshell, extra care needs to be taken when selecting chaotic map and assessing the security of future proposals based on the two-point diffusion strategy schemes.

Cryptanalysis of cross-coupled chaotic maps multi-image encryption scheme

Recently, Patro et al. proposed a multiple gray-scale image encryption scheme based on cross-coupled chaotic maps. The authors claimed the scheme could withstand known plain-text attacks and chosen-plaintext attacks. In this paper, we have thoroughly analysed the Patro et al. algorithm and reported the crucial loopholes. Patro et al. algorithm uses a row-wise and column-wise scrambling operation based on a secret sequence followed by a feed-forward XOR operation generating the cipher image. Exploiting the loopholes of feed-forward XOR operation and high correlation of pixels in standard images, a cryptanalysis algorithm is developed that deciphers the ciphered images generated by Patro et al. algorithm based on cipher-text only attack. Without using the secret keys, the proposed cryptanalysis algorithm successfully deciphers the cipher image and reveals the secret images.

Efficient Privacy-Preserving Spatial Data Query in Cloud Computing

With the rapid development of geographic location technology and the explosive growth of data, a large amount of spatial data is outsourced to the cloud server for reducing the local high storage and computing burdens, but at the same time causes security issues. Thus, extensive privacy-preserving spatial data query schemes have been proposed. Most of the existing schemes use Asymmetric Scalar-Product-Preserving Encryption (ASPE) to encrypt data, but ASPE has proven to be insecure against known plaintext attack. And the existing schemes require users to provide more information about query range and thus generate a large amount of ciphertexts, which causes high storage and computational burdens. To solve these issues, based on enhanced ASPE designed in our conference version, we first propose a basic Privacy-preserving Spatial Data Query (PSDQ) scheme by using a new unified index structure, which only requires users to provide less information about query range. Then, we propose an enhanced PSDQ scheme (PSDQ <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$^+$</tex-math></inline-formula> ) by using Geohash-based <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$R$</tex-math></inline-formula> -tree structure (called <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$GR$</tex-math></inline-formula> -tree) and efficient pruning strategy, which greatly reduces the query time. Formal security analysis proves that our schemes achieve Indistinguishability under Chosen Plaintext Attack (IND-CPA), and extensive experiments demonstrate that our schemes are efficient in practice.

Security analysis of a reversible data hiding scheme in encrypted images by redundant space transfer

Redundant space transfer (RST) encryption can effectively enhance the security and embedding capacity of reversible data hiding in encrypted images. To demonstrate the security risks of RST encryption in the cloud environment, according to the known plaintext image and marked encrypted image(MEI) pairs, this paper proposes a known plaintext attack (KPA) based on hamming-weight of bit block. The proposed KPA method includes two stages. The first stage is to find the correct ciphertext image. For possible block sizes, all possible ciphertext images of MEI are reconstructed by deleting the embedded secret data. The Hamming weight image (HWI) of plaintext and all possible ciphertext images is calculated in m×8n domain (m, n is the image size). When the histogram distance between the plaintext HWI and a possible ciphertext HWI is the minimum, the correct ciphertext image is found. The second stage is to estimate the permutation keys. The bit block characteristic matrix (BBCM) is defined by using that the bit values of plaintext and ciphertext remain unchanged in the process of RST encryption. Based on the intersection of BBCM’s index set, the block permutation key is directly estimated. Then, the bit plane permutation key in each image block is further estimated. Experimental results show that for RST encryption, when the block size is not less than 3 × 3, the block permutation and bit plane permutation key can be estimated in less than 3 min by using one pair of plain–ciphertext. The estimation accuracy of block permutation key is more than 50%, and the estimation accuracy of bit plane permutation key is 10% for Qin’s RST algorithm, most of the content information of the ciphertext image is leaked.

An anti-impersonation attack electronic health record sharing scheme based on proxy re-encryption and blockchain.

Many current electronic medical record (EMR) sharing schemes that use proxy re-encryption and blockchain do not fully consider the potential threat of malicious node impersonation attacks. This oversight could lead to data leakage as attackers masquerade as legitimate users or proxy nodes during the sharing process. To deal with this problem, we propose an EMR sharing scheme based on proxy re-encryption and blockchain to protect against impersonation attacks. First, we prevent the potential threat of impersonation attacks by generating a shared temporary key and assigning tasks to multiple proxy nodes. Second, we use a random function to ensure that the selection of encrypted proxy nodes is fair. Third, we use a combination of blockchain and the InterPlanetary File System to solve the problem of insufficient storage capacity of shared processes and ensure the storage security of EMRs. Through the security proof, our scheme guarantees anti-impersonation, anti-collusion, and anti-chosen plaintext attack capability in the sharing process of EMRs. Additionally, experiments on the blockchain platform, namely Chain33, show that our scheme significantly increases efficiency.

An efficient ID-based cryptographic encryption based on group ring

For most of the traditional IBEs (identity-based encryptions), security totally relies on the safekeeping of private keys. In case the private key is exposed, all the previously generated ciphertext need to be reissued. Due to increased usage of unprotected devices or mobiles, the key exposure is frequent. Therefore, it is important to mitigate the threat originated due to the key exposure in case of IBE. To deal with this issue, in this paper, we construct a novel IBE based on group ring that also provides forward security. We show that the security of our novel IBE is based on the hardness of discrete logarithm problem in group ring. Moreover, against the chosen plaintext attack, we show that it is semantically secure in random oracle model. Finally, we compare our IBE with several other existing IBEs in terms of execution cost.

Concealed Chosen Plaintext Attack on Multiple S-boxes Based Image Encryption

Chosen plaintext attacks (CPA) pose a significant security risk to encryption algorithms. However, it can be difficult to perform such an attack without direct access to the encryption process. This paper introduces a new cryptoanalysis method that uses hidden CPA to analyze image encryption schemes based on substitution boxes (S-boxes) Unlike traditional CPA methods, the proposed algorithm does not require that they can directly into the encryption process. Instead, a hidden attack vector is embedded in the natural host image to reduce the risk of attack detection. By asking the owner of the encryption algorithm to encrypt this encryption image and provide a cipher image, the input vector can be compared with its encrypted counterpart This can have an effective S-box and break encryption the algorithm, which does not interact directly with the encryption process. Experimental results demonstrate that the proposed method can completely recover cipher images in cascading S-box encryption schemes, regardless of the number of S-boxes used. Additionally, it conceals the CPA vector within the host image imperceptibly, achieving a high PSNR of 49.47 dB, indicating minimal visual distortion. Furthermore, our CPA significantly outperforms existing techniques in speed, recovering a grayscale image in just 1.2 seconds. This method provides a simple yet effective cryptanalysis tool to evaluate the security of such image encryption schemes against CPAs.