Provably secure three-party key agreement protocol using Chebyshev chaotic maps in the standard model

Recently, several key agreement protocols based on Chebyshev chaotic maps have been proposed in the literature. However, they can normally achieve “heuristic” security, that is, once drawbacks are found in these protocols, they are either modified to resist the new attacks, or are discarded. Under these circumstances, it is necessary and significant to define standard security models that can precisely characterize the capabilities of the participants and a potent adversary. Hence, we propose to use public key encryption based on enhanced Chebyshev chaotic maps and pseudo-random function ensembles to construct an efficient three-party key agreement protocol under the standard model, in which the adversary is able to make a wider range of queries and have more freedom than the other proposed schemes. In the design of our protocol, we follow the ideas in the recent key agreement protocol of Yang and Cao’s. The proposed protocol is shown to be provably secure if decisional Diffie–Hellman problem, which is based on Chebyshev chaotic maps, is computationally infeasible. To the best of our knowledge, our protocol is the first provably secure 3PAKE protocol using Chebyshev chaotic maps under the standard model.     

Cryptanalysis and improvement of a chaotic map-based key agreement protocol using Chebyshev sequence membership testing

Recently, Gong et al. (Nonlinear Dyn, doi:10.1007/s11071-012-0628-3, 2012) proposed a chaotic map-based key agreement protocol without using smart cards. They claimed that the protocol is secure against password-guessing attacks. However, we show that Gong et al.’s protocol is vulnerable to partition attacks, whereby the adversary can guess the correct password off-line. We also demonstrate that the protocol suffers from a a stolen-verifier attack along with password change pitfalls. Thereafter, we proposed an chaotic map-based key agreement protocol without using smart cards to conquer the mentioned weaknesses. The security analysis of the proposed protocol shows that it is suitable for the applications with higher security requirement.     

An extended chaotic-maps-based protocol with key agreement for multiserver environments

Due to the rapid development and growth of computer networks, there have been greater and greater demands for remote password authentication protocols. Recently, the focus has been on protocols for multiserver environments that run on smart cards. These protocols typically count on the nonce or timestamp to provide protection against the replay attack. However, as Tsaur et al. pointed out, these protocols have some security issues such as disturbance in clock synchronization and vulnerability to the man-in-the-middle attack. In order to solve the above problems, Tsaur et al. proposed a multiserver authentication scheme with key agreement in 2012, and they claimed that their scheme could effectively achieve password-authenticated key agreement while getting around the technical difficulty of implementing clock synchronization in multiserver environments. Unfortunately, we found out that Tsaur et al.’s protocol still has the following weaknesses: (1) inability to resist privileged insider attack, (2) inability to resist known-plaintext attack, (3) inability to provide user anonymity, and (4) lack of perfect forward secrecy. To fix these secure flaws of Tsaur et al.’s protocol, in this paper, we shall propose an improved multiserver authentication protocol with key agreement based on extended chaotic maps. We shall also offer formal proof of smooth execution of the improved authenticated key agreement protocol.     

A secure chaotic maps-based key agreement protocol without using smart cards

To guarantee secure communication, many maps-based key agreement protocols have been proposed. Due to inherent tamper-resistance, most of them are based on smart cards. Unfortunately, the cost of cards and readers makes these protocols costly. In the real world, common storage devices, such as universal serial bus (USB) thumb drives, portable HDDs, mobile phones, and laptop or desktop PCs, are widely used, and they are much cheaper or more convenient for storing user authentication information. These devices do not provide tamper-resistance; it is a challenge to design a secure authentication protocol using these kinds of memory devices. In this paper, we will propose a maps-based key agreement protocol without using smart cards. According to our analysis, the proposed protocol guarantees mutual authentication, and also resists different attacks. Therefore, our protocol is suitable even for practical applications.     

A revised key agreement protocol based on chaotic maps

Very recently, Chen et al. proposed a security-enhanced key agreement protocol based on Chebyshev chaotic map. They claimed that the proposed protocol can achieve session key agreement shared among the server and user with security and users anonymity. Although, in this paper, we will prove that Chen et al.’s protocol cannot guarantee security and user anonymity against internal adversary who is a legal user. Furthermore, we give some improvements to dominate the mentioned shortcomings. The analysis shows that our proposed improvements are secure and efficient.     

A three-party password-based authenticated key exchange protocol with user anonymity using extended chaotic maps

In this paper, we propose a scheme utilizing three-party password-based authenticated key exchange protocol with user anonymity using extended chaotic maps, which is more efficient and secure than previously proposed schemes. In order to enhance the efficiency and security, we use the extended chaotic maps to encrypt and decrypt the information transmitted by the user or the server. In addition, the proposed protocol provides user anonymity to guarantee the identity of users, which is transmitted in the insecure public network.     

Analysis and improvement of a chaos-based symmetric image encryption scheme using a bit-level permutation

Recently, a chaos-based symmetric image encryption scheme using a bit-level permutation was proposed. In this paper, we analyze the potential flaws in Zhu’s algorithm in detail and develop a chosen-plaintext attack and chosen-ciphertext attack on Zhu’s algorithm. The proposed attack indicates that the Arnold cat map applied directly in image encryptions is not suitable for cryptography. We also propose the corresponding improved scheme. The improved scheme preserves the merits of the original one.     

Chaos-based image encryption with total shuffling and bidirectional diffusion

This paper proposes a chaos-based image encryption method with permutation–diffusion architecture, in which a spatiotemporal chaotic system modeled by coupled map lattices is used to generate random sequences. In the permutation step, the permutation is generated of the same size as the plain image, which shuffles the positions of image pixels totally. In order to effectively generate this large permutation, we present a fast method to construct permutation by combining several small permutations, where small permutations are directly generated by a chaotic system. In the diffusion step, bidirectional diffusion is used to diffuse each pixel to all other pixels of the image. A key stream buffer is utilized to cache the random numbers generated by the chaotic system, and each pixel is ciphered by a random number chosen from the key stream buffer according to its previous pixel. The experimental results and analysis by using several security measures show that the proposed image encryption scheme has high security and efficiency.     

An image encryption scheme based on chaotic tent map

Image encryption has been an attractive research field in recent years. The chaos-based cryptographic algorithms have suggested some new and efficient ways to develop secure image encryption techniques. This paper proposes a novel image encryption scheme, which is based on the chaotic tent map. Image encryption systems based on such map show some better performances. Firstly, the chaotic tent map is modified to generate chaotic key stream that is more suitable for image encryption. Secondly, the chaos-based key stream is generated by a 1-D chaotic tent map, which has a better performance in terms of randomness properties and security level. The performance and security analysis of the proposed image encryption scheme is performed using well-known ways. The results of the fail-safe analysis are inspiring, and it can be concluded that the proposed scheme is efficient and secure.     

Cryptanalysis and improvement of a three-party key agreement protocol using enhanced Chebyshev polynomials

Three-party key agreement protocol is an important cryptographic mechanism for secure communication, which allows two parties authenticate each other with the help of a trusted server. Very recently, Lai et al.’s proposed a novel three-party key agreement protocol using the enhanced Chebyshev chaotic map and claimed their protocol could withstand various attacks. Unfortunately, in this paper, we will show their protocol is vulnerable to the privileged insider attack and the off-line password guessing attack. To solve the problems, we propose an improved three-party key agreement protocol using the enhanced Chebyshev chaotic map. Security analysis and performance analysis show our protocol not only could withstand various attacks, but also has similar performance. Therefore, it is very suitable for practical applications.     

A secure biometric-based remote user authentication with key agreement scheme using extended chaotic maps

Recently, biometric-based remote user authentication schemes along with passwords have drawn considerable attention in research. In 2011, Das proposed an improvement on an efficient biometric-based remote user authentication scheme using smart cards and claimed his scheme could resist various attacks. However, there are some weaknesses in Das’s scheme such as the privileged insider attack and the off-line password guessing attack. Besides, Das’s scheme also cannot provide user anonymity. To overcome these weaknesses, we shall propose a secure biometric-based remote user authentication with key agreement scheme using extended chaotic maps. The proposed scheme not only can resist the above-mentioned attacks, but also provide user anonymity.     

A chaotic maps-based authenticated key agreement protocol with strong anonymity

In wireless communication environments, the authenticated key agreement with user anonymity is important. Recently, many chaotic maps-based anonymous authenticated key agreement protocols have been proposed. Tseng et al. applied Chebyshev chaotic maps to propose an anonymous key agreement protocol. Unfortunately, Niu et al. demonstrated that Tseng et al.’s protocol cannot protect the user anonymity and it suffers from insider attacks. Xue et al. improved Tseng et al.’s protocol. However, we have found that their improved protocol still cannot provide strong anonymity and it is vulnerable to the man-in-the-middle attack. To remove these weaknesses, we have proposed a novel chaotic maps-based authenticated key agreement protocol. The proposed protocol cannot only resist these attacks, but also provide strong anonymity.     

Provably secure dynamic identity-based three-factor password authentication scheme using extended chaotic maps

With the aim of guaranteeing secure communication through public networks, three-factor password authentication (TF-PWA) scheme plays a key role in many internet applications. Since in TF-PWA scheme, the communicating entities can mutually authenticate each other and generate a shared session key, which will be used for secure exchange of messages in succeeding communication among them. As a result, the TF-PWA schemes gain enormous consideration in recent years. More recently, due to light-weight features of the extended chaotic map, it is also extensively applied in designing of public key encryption, key agreement, image encryption, S-box, hash function, digital signature, password authentication, etc. The aim of this paper was to design a dynamic identity-based three-factor password authentication scheme using extended chaotic map (ECM-TF-PWA) in the random oracle model. The proposed scheme is provably secure based on the intractability assumption of chaotic map-based Diffie–Hellman problem. The informal security analysis gives the evidence that our scheme protects all attacks and provides functionality attributes that are needed in a three-factor authentication system. Besides, the performance discussion shows that our scheme performs better than others in respect of computation and communication cost.     

A new digital signature scheme based on chaotic maps

In the present e-commerce and e-government era, digital signatures have become more and more important. Digital signature algorithms can be categorized based on the type of security suppositions, for example discrete logarithm, factorization hard-problems, and elliptic curve cryptography, which are all currently believed to be unsolvable in a reasonable time period. Recently, cryptosystems based on chaotic maps have been proposed. Due to some subtle and close relationships between the properties of traditional cryptosystems and chaotic systems, the idea of chaotic systems with applications to cryptography has received a great deal of attention from researchers from a variety of disciplines. Therefore, to enhance system security, we explore the implementation of a digital signature algorithm based on both cryptographic and chaotic system characteristics. We also give a proof that the security of the proposed scheme can protect against the known key attacks.     

Unkeyed hash function based on chaotic sponge construction and fixed-point arithmetic

Chaotic maps have various properties that mirror the security requirements of cryptographic algorithms. As such, researchers have utilized them in the design of algorithms such as hash functions. Although there exist a wide range of chaos-based hash functions in literature, most of them are designed in an ad hoc manner rather than relying on well-established design paradigms. In addition, they are commonly implemented using floating-point operations which are inefficient as compared to their bitwise counterparts. The combination of convoluted designs and floating-point representation also leads to hash functions that are difficult to analyze; therefore, claims of security cannot be verified easily. These issues are some of the reasons why chaos-based hash functions have not seen widespread use in practice. This paper proposes a new unkeyed hash function based on a chaotic sponge construction and fixed-point arithmetic to overcome the aforementioned problems. The use of a sponge construction provides provable security justifications, whereas the use of fixed-point arithmetic allows chaotic map operations to be implemented using bitwise operations. The combination of these design elements leads to a design that is both efficient and facilitates future cryptanalysis for security verification. Security and performance evaluations indicate that the proposed hash function has near-ideal diffusion, confusion, collision resistance, and distribution properties in addition to a hashing speed that is at least on par with the current state of the art in chaos-based hash functions.

     

A theoretical analysis of piezoelectric/composite anisotropic laminate with larger-amplitude deflection effect,Part I: Fundamental equations

Considering the effects of both the different material properties of composite layers and the poling directions of piezoelectric layers, we utilized the assumption of the simple-higher-order shear deformation theory to model and analyze the laminated composite plate integrated with the random poled piezoelectric layers. Further, the generalized Hamilton’s variation principle for electro-elasticity was employed to deduce the fundamental equations of piezoelectric/composite anisotropic laminate, i.e. the governing equations and boundary conditions. For the special requirement of the larger-amplitude deflection of smart structures, the Von Karman strains were used to account for the geometric nonlinear effect of the practical larger-amplitude deflection on the electro-elastic behavior of smart composite structures. Moreover, the sensor equations were also carried out with considering the large-amplitude deflection effect of smart composite structures.     

Brief review on application of nonlinear dynamics in image encryption

Chaos-based cryptology has become one of the most common design techniques to design new encryption algorithms in the last two decades. However, many proposals have been observed to be weak against simple known attacks. However, security of proposals cannot be proved. An analysis roadmap is needed for the security analysis of new proposals. This study aims to address this shortcoming. Analysis and test results show that many chaos-based image encryption algorithms previously published in the nonlinear dynamics are actually not as secure as they are expressed although these algorithms do pass several statistical and randomness tests. A checklist has been proposed to solve these problems. The applications of the proposed checklist have been shown for different algorithms. The proposed checklist is thought to be a good starting point for researchers who are considering to work in chaos-based cryptography.     

Stiffness reduction of cracked general symmetric laminates using a variational approach

In this paper, stiffness reduction of general symmetric laminates containing a uniform distribution of matrix cracks in a single orientation is analyzed. An admissible stress field is considered, which satisfies equilibrium and all the boundary and continuity conditions. This stress field has been used in conjunction with the principle of minimum complementary energy to get the effective stiffness matrix of a cracked general symmetric laminate. Natural boundary conditions have been derived from the variational principle to overcome the limitations of the existing variational methods on the analysis of general symmetric laminates. Therefore, the capability of analyzing cracked symmetric laminates using the variational approach has been enhanced significantly. It has been shown that the method provides a rigorous lower bound for the stiffness matrix of a cracked laminate, which is very important for practical applications. Results derived from the developed method for the properties of the cracked laminates showed an excellent agreement with experimental data and with those obtained from McCartney’s stress transfer model. The differences of the developed model with McCartney’s model are discussed in detail. It can be emphasized that the current approach is simpler than McCartney’s model, which needs an averaging procedure to obtain the governing equations. Moreover, it has been shown that the existing variational models are special cases of the current formulation.     

A novel fast chaos-based algorithm for generating random permutations with high shift factor suitable for image scrambling

The good qualities of permutations with a high shift factor in terms of speech scrambling have been proven in the last 20 years. Nevertheless, the absence of a fast algorithm for generating them has limited their use in cryptographic applications. In this paper, we propose a new fast chaos-based method for generating random permutations with a high shift factor, and we compare it with some similar schemes, classical or chaos-based. The permutations generated by the proposed method have very few fixed points, too, making them theoretically suitable for image scrambling or for use as a diffusion stage in an image cryptosystem. We prove this fact using some standard indicators as MSE, UACI, NPCR, PCC, etc. and by comparisons to the results obtained for other algorithms of this type. All the results obtained are very good, including a speed of pixels permutation of 14 MB/s, allowing us to say that the proposed algorithm is a fast and efficient one, which can be used even in real-time scrambling.     

An extended chaotic maps based user authentication and privacy preserving scheme against DoS attacks in pervasive and ubiquitous computing environments

As the era of pervasive and ubiquitous computing comes close, hand-held and smart devices are expected to achieve the dream of all time everywhere computing. Remote user authentication is important to verify the legitimacy of a login user over an insecure communication channel. Furthermore, in order to protect user privacy such that others cannot trace login users by eavesdropping the communication messages, several researchers proposed some dynamic ID-based remote user authentication schemes for providing user anonymity. On the other hand, the denial-of-service (DoS) attacks may make legal users unable to access a remote server by intercepting the authentication message which a login user sends to the remote server. It will make the latest user identities kept by login user and the remote server differ from each other. To ensure user anonymity and prevent such DoS attacks, we propose an extended chaotic map and dynamic ID-based user authentication scheme against DoS attacks. The proposed scheme is suitable for use in pervasive computing environments such as online financial authentication since it can ensure security while maintaining efficiency.