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Big data, cloud computing and other hot areas are the use of personal information, but in the process of using this data, a large number of improper behavior is used to steal personal information. Most of the encryption algorithms in common use nowadays are based on ones that are no longer absolutely secure, such as RSA attacked by factorization, elliptic curves attacked by Pollard's lambda algorithm, and symmetric encryption algorithms attacked by collisions. In this paper, an integrated encryption and compression algorithm is designed, firstly, the data is transformed into the form of matrix, and the Jordan decomposition is used for preliminary compression and encryption from the two-dimensional point of view, and then based on the sparsity of matrix vectors, the compression-aware technique is used for compressing the set of key vectors, and the ciphertext group J produced by Jordan decomposition (which is a string of numbers with matrix diagonal length base √2 N), as well as the set of key vectors Y and the intermediate value Θ produced by compression awareness are obtained in the end. This sidesteps the common algorithms that have already been breached and is able to combine better encryption performance with compression performance while being innovative. [ABSTRACT FROM AUTHOR]

Panda and Chattopadhyay proposed "A Hybrid Algorithm for RSA Cryptosystem" in 2017, they modified well-known algorithm RSA into modulo four prime numbers. Later, Gondaliya, Savani, Dhaduvai and Hossain proposed "Hybrid Security RSA Algorithm in Application of Web Service" in 2018. However, we found that these two papers are highly similar, and the main focus of this article is how to determine the victim the (suffer) and the perpetrator (the plagiarist). [ABSTRACT FROM AUTHOR]

IoT devices typically encompass objects or devices equipped with software and internet connectivity, allowing them to collect data. They have limited processing power, memory, and storage. These limitations can make it difficult to secure these devices, as traditional security measures may not be practical. Implementing security for IoT devices can be challenging due to these characteristics, but several steps can be taken to mitigate these challenges. Elliptic Curve Cryptography (ECC) can secure resource constrained IoT devices by providing a more efficient method of encryption and authentication than traditional methods such as RSA. In this paper, we analyzed the lightweight cryptographic algorithm ECC for securing resource-constrained devices such as IoT and evaluated its performance compared to the RSA cryptosystem. The analysis result indicates that ECC is considered to provide stronger security than RSA for the same key length. The CoAP protocol is applied to devices with limited resources, and an examination of its impact is conducted, considering three key performance metrics: CPU usage, bandwidth efficiency, and message communication latency. [ABSTRACT FROM AUTHOR]

With the increasing number of computer network users, the problem of network communication security has become more and more serious. Encryption technology, as one of the key technologies for securing communication, has important research and application values. However, the security of conventional encryption methods is gradually challenged, and at the same time, traditional encryption algorithms require a large amount of computing resources, which makes it difficult to realize real-time encryption and decryption operations. Therefore, how to improve the confidentiality and efficiency of computer network communication security encryption system has become a current urgent problem to be solved. This paper firstly discussed the analysis of its application in the computer network communication security encryption system based on the ant colony optimization (ACO) algorithm. Through the theoretical analysis of the ACO algorithm in terms of bioheuristic optimization algorithm and the analysis of the characteristics of the algorithm, the optimization scheme of key distribution based on the ACO algorithm was discussed. Then, the differences between the ACO algorithm and the traditional encryption algorithm in terms of encryption duration, key distribution time, encryption strength and random number generation speed were further analyzed and verified by experimental data. The data results showed that the key distribution of the encryption system using the ACO algorithm had higher security and better performance compared with the traditional key distribution algorithm. By counting and comparing the data, it was found that the ACO algorithm showed very obvious advantages in terms of encryption and decryption time, key distribution time, encryption strength and random number generation. This indicates that the ACO algorithm has very important application prospects in computer network communication security encryption systems. [ABSTRACT FROM AUTHOR]

• The effect of synchronisation on the master-slave NNs with time delay is examined. • The NN's chaotic attractor is reconstructed using the fractal interpolation. • Reconstructed chaotic sequence is applied in image encryption. • Image encryption is carried out using RSA algorithm. • Various statistical measures are used to verify the efficacy. This paper examines synchronization of delayed chaotic neural networks with impulsive control, event-triggered impulsive control, and event-triggered delayed impulsive control. Lyapunov-based event-triggered mechanism is constructed to derive few sufficient conditions in terms of Linear Matrix Inequalities (LMIs). The feedback and event-triggered gain matrices are evaluated with the help of numerical packages. The fractal interpolation functions are employed to reconstruct the chaotic sequence of the neural networks since the chaotic attractor has self-similar properties and coincides with the fractal functions. In this study, a linear fractal interpolation is used to reconstruct both the master-slave chaotic attractor and the encrypted chaotic attractor, with optimized scaling factors. Finally, an application of the image encryption algorithm is given in terms of RSA public-key cryptosystems, permutation, and finite field diffusion for the chaotic sequence generated by fractal interpolation functions. [ABSTRACT FROM AUTHOR]

Mobile Crowd Sensing (MCS) is an effective way to tackle day-to-day life problems nowadays, from Google Maps to Uber cabs. It is an effective and efficient way of data collection, processing and delivery of results to the users, from the users and for the users. All the entities that make up a Mobile crowd sensing system be it a worker, requester or miner can be represented as a node. All the nodes interact together to make a trustworthy system where there is a limited or no scope of deception. The traditional approach to crowd sensing gives little importance to communication between the nodes and in most cases, it assumes the communication happens through a secure channel and ignores the potential hazards. We propose a novel blockchain-based decentralized and collaborative approach to communicate between the nodes which would help workers/users to interact in real-time and solve conflicts should there be any. To decentralize we use the blockchain technology to overcome single point of failure which is a major issue, as mentioned peer-to-peer link between nodes is more expensive only but it improvise the security and privacy concerns by using the consensus mechanism. With the aim of improving the traditional communication technology between the nodes, we propose a mechanism based on Kafka, blockchain and RSA encryption for continuous exchange of data between the nodes which would help to enhance the security and efficiency of the system. [ABSTRACT FROM AUTHOR]

Quantum computing, based on quantum mechanical principle, can potentially provide significant advantages over classical computing. This advantage of quantum computing provides solutions to many previously unsolvable problems in secure communication and finance. IoT is an emerging technology that deals with a large amount of data. The data communicated in IoT need to be secured. The existing security architecture of IoT is based on cryptographic algorithms such as RSA and ECC. Quantum computing had a significant impact on the security of these algorithms. Therefore, our work analyses the security concerns of IoT smart applications and quantum-based solutions. This article provides a survey of quantum computing fundamentals and the impact of quantum computing on IoT security. Thus, this paper aims to provide a wide view of quantum-enabled IoT communication. The main challenges in implementing quantum-enabled communication are also analyzed in our work. [ABSTRACT FROM AUTHOR]

One of the critical goals of advanced cryptography is to protect data privacy. Although protecting sensitive data has always been essential, it has become much more due to the widespread use of cloud services. Conventional encryption schemes have one drawback: data must be decrypted before processing. Best practices have long recommended that data must be secured at rest and in motion when using public cloud services, i.e., we need encryption at the storage as well as at processing levels. Homomorphic encryption is an advanced cryptographic approach in which the processing of encrypted data is possible. In this paper, we have presented the insights required for understanding homomorphic encryption approaches. We examined and compared two partial homomorphic techniques, RSA and Pallier algorithm based on efficiency, base method, and homomorphic property. [ABSTRACT FROM AUTHOR]

The recent innovations in network application and the internet have made data and network security the major role in data communication system development. Cryptography is one of the outstanding and powerful tools for ensuring data and network security. In cryptography, randomization of encrypted data increases the security level as well as the Computational Complexity of cryptographic algorithms involved. This research study provides encryption algorithms that bring confidentiality and integrity based on two algorithms. The encryption algorithms include a well-known RSA algorithm (1024 key length) with an enhanced bit insertion algorithm to enhance the security of RSA against different attacks. The security classical RSA has depreciated irrespective of the size of the key length due to the development in computing technology and hacking system. Due to these lapses, we have tried to improve on the contribution of the paper by enhancing the security of RSA against different attacks and also increasing diffusion degree without increasing the key length. The security analysis of the study was compared with classical RSA of 1024 key length using mathematical evaluation proofs, the experimental results generated were compared with classical RSA of 1024 key length using avalanche effect in (%) and computational complexity as performance evaluation metrics. The results show that RBMRSA is better than classical RSA in terms of security but at the cost of execution time. [ABSTRACT FROM AUTHOR]

The source code of any software is confidential and its intellectual property has to be protected from the malicious intent of the attackers. The present work offers the architecture of a cloud model for secure intellectual property protection of arithmetic expressions in a source code. The data obfuscation techniques are meant to be applied on different types of arithmetic operators in an arithmetic expression, "The required algorithms proposed in this paper are named as i) 'Adaptive Number Generation' obfuscation to be applied on all operators ii) Obfuscation by 'Carry Padding' to be applied on '+' operator iii) Three Obfuscations by 'Mixed Boolean Arithmetic' to be applied on '+', '-' and '*' operators and iv) ' A-RSA +′ obfuscation to be applied on '+' operator." Experimentations are conducted to validate their functionality and performance metrics measurements in terms of Cyclomatic complexity, Time complexity, Space complexity and Potency analysis are carried out on a set of benchmark source codes and it has been found that there is only a very slight increase of 6.57% number of lines of code in the obfuscated codes compared to the corresponding original, the average increase in the obfuscated code's execution time is 29% and the estimated average potency given by the proposed obfuscation techniques is 1.06% which is also greater than one. Also, a mathematical model is developed to estimate the Mean Obfuscated Source Code Cloud Delay (MOSCD), which is the time duration in which the obfuscated source code is available physically at the cloud server to face any possible Man-At-The-End (MATE) attacks. An attacker may build a control flow graph (CFG) out of the source code to perform attacks based on static and dynamic analysis-based reverse engineering. The time required to generate a CFG is also estimated and in comparison, with the MOSCD, it is observed that the minimum CFG build time is almost three multiples of the maximum MOSCD value we received in our experimentations it is proved that our model is strong to thwart away any possible MATE attacks. • The source code of any software is confidential and its intellectual property has to be protected from the malicious intent of the attackers. • The present work offers the architecture of a cloud model for secure intellectual property protection of arithmetic expressions in a source code. • The present work offers several data obfuscation techniques to be applied on all the arithmetic operators. • The proposed secure cloud model can able to withstand various security analysis attacks at the cloud at the expense of a slight increase in the system overheads. [ABSTRACT FROM AUTHOR]

Colombia government wants to implement electronic voting. However, the existing electronic voting protocols only include some of the required security features and Colombia needs a protocol with all these features to ensure fraud-free elections. In this paper, we present the design of SIVP (Secure Internet Voting Protocol), a new voting protocol for electoral processes, based on blind signatures and public key cryptography. This protocol has six phases and provides: eligibility, democracy, privacy, verifiability, accuracy, fairness, robustness, receipt-freeness and coercion-resistant. Also, we compare the number of cryptographic operations per phase of SIVP with other four protocols and conclude that the computational load of our protocol is not excessively high despite including more security features. [ABSTRACT FROM AUTHOR]

With growing interest in Accident Tolerant Fuels (ATF) such as Fully Ceramic Micro-Encapsulated (FCM) fuel, explicit modeling processes play an increasingly important role in the precise simulation of particle transport in stochastic media. Current explicit modeling methods in RMC utilize Random Sequential Addition (RSA), where particles are randomly and sequentially packed into fuel. However, at high packing fractions, the RSA process becomes highly inefficient as simulation times increase exponentially. An improved RSA algorithm was developed by employing Octree-based Acceleration and Parallel Processing. The accuracy of the algorithm was then verified against particle distributions generated via Serpent2. The Iterative RSA-DEM Method for simulating stochastic geometry was then developed to generate explicit particle distributions beyond the RSA infinite-time saturation limit. The results show that the improved algorithms can produce highly accurate results with greatly reduced simulation time, with the capability to be easily adapted for different nuclear fuel configurations. • We have successfully developed a precise and effective RSA algorithm for the purposes of explicitly modeling dispersion fuel. With the new algorithm, we are able to induce more than 99% in time savings when generating particles near the particle packing fraction limit. • Using the algorithm mentioned above, we have successfully developed the capability to simulate annular fuel designs in RMC code, and we have simultaneously verified the capabilities of the algorithm against particle distributions generated in Serpent2. • We showcase an application of this Improved RSA algorithm with the Iterative RSA-DEM Method, a novel method to develop particle packings for volumetric fractions above the infinite-time saturation limit of RSA. [ABSTRACT FROM AUTHOR]

In this paper, we consider five variants of the RSA cryptosystem, where the modulus is N = p q , and the public key e and the secret key d satisfy e d − k (p 2 + p + 1) (q 2 + q + 1) = 1 or e d − k (p 2 − 1) (q 2 − 1) = 1. Our results show that if a certain amount of the most significant bits of p are known so that | p − p 0 | = N β with a known p 0 , then one can factor the RSA modulus with a better bound than low private exponent attacks. We also present the experimental results to verify our analysis. [ABSTRACT FROM AUTHOR]

The multi-cloud-based resource allocation is based on multiple constraints and multiple configurations that may vary based on customer requirements and cloud service providers' schemes. Here, security is a serious concern that can be ensured by an authentication scheme based on the Self-Adaptive Flower Pollination based RSA (SA-FPRSA) scheme to ensure data integrity. The SA-FPRSA plays an initial role in ensuring security by enabling authenticated data availability. On the other hand, the resource allocation to the Virtual Machine (VM) is a challenging task due to overwhelmed data in a VM that may face unnecessary energy consumption and time complexity issues. Therefore, the proposed model has introduced a Self-adaptive Heap-based optimizer (HBO) for Multi-Cloud based resource allocation. The performance of the models is evaluated. The proposed model attained an Efficiency of 99.09% and Security of 98.72%. Thus, from the results, the recommended model is proven to be better than the existing models. [ABSTRACT FROM AUTHOR]

Sensitive Health Information (SHI) is a developing patient-centric model of medical data exchange, which is frequently outsourced to be stored at third party servers. Though, there have been various privacy issues as SHI could be disclosed to the unauthorised and third parties. This is a promising method to encrypt the SHI before outsourcing to assure the patients' control over access to their own SHI. However, challenges like scalability in key management and flexible access have remained the most significant issues toward achieving fine-grained, cryptographically data access control. In this paper, the authors proposed a novel patient-centric system model for access control to SHIs stored in semi-honest servers. For fine-grained and scalable access control for SHIs, authors have proposed an encryption technique which is an improvement over RSA techniques to encrypt every patient's SHI file. To different from previous works in secure data transmission, the authors focus on the data owner and divide users into several domains in SHI, which greatly decrease the key management complexity for data owners and users. Comprehensive analytical and experimental results are presented which reflect the efficiency of the proposed approach. [ABSTRACT FROM AUTHOR]

This paper investigates a novel RSA-like cryptosystem proposed by Murru-Saettone. This cryptosystem is constructed from a cubic field connected to the cubic Pell equation and Redei rational functions. The scheme is claimed to be secure against the Wiener-type attack. However, in this paper, we show a Wiener-type attack that can recover the secret key from the continued fraction constructed from public information. [ABSTRACT FROM AUTHOR]

Nowadays the resiliency is the main property in any system especially communication infrastructures. Unfortunately, many developers are working on making programs more resilient and reliable, facing people who want to use leaks in an unethical way, and breaking (or trying to break) largely used one-way functions such as MD5, SHA-1, or RSA based algorithms. As an alternative, exploiting Physically Unclonable Functions (PUF) can be a good solution to improve the level of robustness and security for encryption by adding a pinch of randomness when manufacturing it, while enabling the use of true randomness. A PUF is characterized by a 'digital fingerprint', as an identifier, derived from a complex physical object or device, such as IoT. It is like a black box, which takes an input, called Challenge, and producing an output, called Response. Actually, they are different types of PUF, Weak and Strong, depending on the amount and the heterogeneity of challenge-responses pairs. This paper provides the fundamental concepts and techniques needed to develop a robust and resilient PUF-based communication system. This objective is achieved by mathematically defining FUFs, from foundations to the attacks, by relying on more concepts around PUF, such as cryptanalysis, or asymptotic notations. Also, we develop a mutual communication protocol that ensures security between different parties peer-to-peer devices, and devices-server. We concertize the provided fundamentals in a concrete framework that is experimentally validated. [ABSTRACT FROM AUTHOR]

Ring signature and group signature are two major cryptographic primitives providing users anonymity and authentication simultaneously. While both primitives enable any user to sign messages as a member of a set of users, the feature of ring signature is that a signer can choose a group in an ad-hoc manner, which is called a ring, by itself. Conversely, in group signature, a group membership is managed by some trusted third party, which is called a group manager, and an (appropriate) accountability is provided for the group manager to identify illegal anonymous signers. Accountable ring signature (ARS) is a cryptographic primitive combining the features of ring signature and group signature. ARS allows signers to choose their groups (rings) in an ad-hoc manner, and at the same time, maintain accountability by forcing them to select a designated opener who can identify them. In this paper, we propose the first ARS scheme with O (log ⁡ n) signature size in the standard model (without depending on the random oracle methodology), where n is the size of a ring. More precisely, we propose a new generic construction of ARS based on (standard) signature, (standard) public key encryption, non-interactive zero-knowledge proof system, somewhere perfectly binding hash function, and public key encryption with non-interactive opening. All building blocks for our ARS scheme can be obtained under the decisional linear (DLIN) assumption over bilinear groups. [ABSTRACT FROM AUTHOR]

Due to the advancement of cloud computing, public key encryption with equality test has become a hot topic in the cryptography community. The notion was extended to the identity-based setting to obtain a new primitive, called identity-based encryption with equality test (IBEET). To the best of our knowledge, there are two categories of authorization mechanisms for IBEET: ciphertext-specified authorization and user-specified authorization. However, these authorizations are not applicable for some scenarios. Motivated by this, we propose in this paper a new primitive, called identity-based encryption with equality test and datestamp-based authorization mechanism (IBEET-DBA). In the primitive, the data owner can control the validity of trapdoor by embedding datestamp into it. The cloud server can only obtain the correct equivalence results on the ciphertexts which are generated within the valid period of trapdoor. In this paper, we formally define this primitive and its security notion. Moreover, we propose the first IBEET-DBA scheme and prove its security. [ABSTRACT FROM AUTHOR]

Partial key exposure attacks on RSA have been intensively studied by using lattice-based Coppersmith's methods. Ernst et al. (Eurocrypt'05) studied the problem by considering three attack scenarios; (1) the most significant bits (MSBs) of a secret exponent d known, (2) the least significant bits (LSBs) of d known, (3) both the MSBs and the LSBs of d known. The proposed attacks were valuable since they were the first results to handle full size exponents e. Takayasu and Kunihiro (SAC'14, Theoretical Computer Science'19) proposed improved attacks for (1) and (2) when d is sufficiently small, i.e., d < N 0.5625 for (1) and d < N 0.368 for (2), by utilizing a linearization technique. In this paper, we extend Takayasu-Kunihiro's attacks and improve Ernst et al.'s attack for (3). In particular, our attack contains Takayasu-Kunihiro's attacks for (1) and (2) as special cases when the amount of given LSBs and MSBs are zero, respectively. Furthermore, as opposed to Takayasu-Kunihiro's attacks, our improvement against Ernst et al.'s attack is not limited to small secret exponents such as d < N 0.5625. Indeed, we are able to improve Ernst et al.'s attack almost up to full size decryption exponents, i.e., even when d is close to N. Technically, the extension is not straightforward. We first modify Takayasu-Kunihiro's lattice basis matrix for (2), so that it is compatible to embed the given MSBs. The modification is crucial for embedding both the MSBs and the LSBs simultaneously to the matrix. [ABSTRACT FROM AUTHOR]

In the secure multicast communication, data is transmitted in such a manner that only authorized group members are able to receive the data. The main challenging issue in dynamic and secure multicast communication is to design a centralized group key distribution protocol with minimum computation and storages complexity. This paper, proposes a more efficient centralized group key distribution (CGKD) protocol that minimizes the computation cost of key server (KS) during key updating. The computation cost of members is balanced during key recovery. This reduction in computation cost of KS is achieved by performing one addition, one multiplication and one encryption during single member join and one subtraction, one division and one encryption during a single member leave operation. Moreover, the storage complexity of KS is also minimized. Further, this paper also proposes an extended CGKD protocol based on clustered tree which is very scalable and efficient to deal with enormous membership changes. By comparing with existing similar protocols, the proposed protocol has significantly reduced computation and storage complexity of KS while maintaining less and balanced communication overhead of KS and storage load of each group member. The proposed protocol is implemented and tested on key-star and cluster tree based structure. The experimental results show that the proposed protocol is efficient in terms of computational overhead of KS and group members. [ABSTRACT FROM AUTHOR]

Complex, concentrated alloys (CCAs) containing refractory principal elements and Al can have microstructures with disordered body-centered cubic (BCC) and ordered B2 phases that are remarkably similar to superalloys. The simple idea of copying superalloy microstructures in these BCC-based refractory alloys introduces a set of audacious challenges. BCC metals and B2 compounds are often brittle at room temperature; the B2 phase is unstable in refractory-Al binaries and reasons for its stability in higher-order systems are a mystery; and many refractory metals and alloys display catastrophic oxidation. Here we discuss opportunities and challenges to develop RSAs as new high temperature structural materials. Image, graphical abstract [ABSTRACT FROM AUTHOR]

Tightly secure cryptographic schemes have been extensively studied in the fields of chosen-ciphertext secure public-key encryption (CCA-secure PKE), identity-based encryption (IBE), signatures and more. We extend tightly secure cryptography to inner product functional encryption (IPFE) and present the first tightly secure schemes related to IPFE. We first construct a new IPFE schemes that are tightly secure in the multi-user and multi-challenge setting. In other words, the security of our schemes do not degrade even if an adversary obtains many ciphertexts generated by many users. Our schemes are constructible on a pairing-free group and secure under the matrix decisional Diffie-Hellman (MDDH) assumption, which is the generalization of the decisional Diffie-Hellman (DDH) assumption. Applying the known conversions by Lin (CRYPTO 2017) and Abdalla et al. (CRYPTO 2018) to our schemes, we can obtain the first tightly secure function-hiding IPFE schemes and multi-input IPFE (MIPFE) schemes respectively. Our second main contribution is the proposal of a new generic conversion from function-hiding IPFE to function-hiding MIPFE, which was left as an open problem by Abdalla et al. (CRYPTO 2018). We can obtain the first tightly secure function-hiding MIPFE schemes by applying our conversion to the tightly secure function-hiding IPFE schemes described above. [ABSTRACT FROM AUTHOR]

In RSA, private exponent is usually obtained from the preselected public exponent by extended Euclid algorithm and is roughly the same bit size as a modulus number. If the private exponent is preselected as in rebalanced RSA, then the public exponent obtained by extended Euclid algorithm is roughly the same bit size as a modulus number. Hence, it is not easy to reduce both public exponent and private exponent (or CRT private exponents) in RSA key generation. In order to reduce both public exponent and CRT private exponents, the methods to search the modulus number after selecting proper public exponent and private exponent have been proposed in recent researches. However, these methods all have complicated key generation because prime generation module developed for RSA cannot be used. In this paper, we present a method to reduce both public exponent and CRT private exponents after selecting the prime numbers and propose a fast rebalanced RSA signature scheme with small public exponent. Our scheme is advantageous than other schemes in the aspect of using typical prime generation. That is, key generation is not complicated in our scheme. [ABSTRACT FROM AUTHOR]

This paper demonstrates how to design constrained pseudorandom functions (CPRF) and their various extensions from any public key functional encryption (FE) with standard polynomial security against arbitrary collusions. More precisely, we start by presenting a CPRF construction that supports constraint predicates realizable by arbitrary polynomial-size circuits , based on polynomially-hard public key FE and one way functions. Next, we augment our CPRF construction with the verifiability feature, relying only on a minimal additional assumption, namely, the existence of standard public key encryption (PKE). Finally, we show how to achieve privacy for the issued keys in the context of programable pseudorandom functions (PPRF), which is an enhanced variant of CPRF supporting puncturing constraints, employing polynomially-hard FE and one way functions. All prior works addressing the above problems either work for very restricted settings or rely on highly powerful yet little-understood cryptographic objects such as multilinear maps or indistinguishability obfuscation (IO). Although, there are known transformations from FE to IO , the reductions suffer from an exponential security loss and hence cannot be directly employed to replace IO with FE in cryptographic constructions at the expense of only a polynomial loss. Thus, our results open up a new pathway towards realizing numerous variants of CPRF , which are interesting cryptographic primitives in their own right and, moreover, have already been shown instrumental in a staggering range of applications, both in classical as well as in cutting edge cryptography, based on progressively weaker and well-studied cryptographic building blocks. Our work can also be interpreted as yet another stepping stone towards establishing FE as a substitute for IO in cryptographic applications. In order to achieve our results we build upon the prefix puncturing technique developed by Garg et al. [CRYPTO 2016, EUROCRYPT 2017] [42,43]. [ABSTRACT FROM AUTHOR]

Alwen et al. in Eurocrypt 2010, showed that an identity-based hash proof system (IB-HPS), where IB-HPS generalizes the notion of hash proof system (HPS) to the identity-based setting, almost immediately yields an identity-based encryption (IBE) scheme which is secure against partial leakage of the target identity's decryption key. That is, an IBE scheme with bounded leakage resilience can be naturally created from an IB-HPS. However, in the real world, the leakage is unbounded, and any adversary can break the security of cryptography shceme by performing continuous leakage attacks. To further increase the practicability, a cryptography scheme must hold the claimed security in the continuous leakage setting. Dodis et al. in FOCS 2010, showed a generic method how to create a cryptography shceme with continuous leakage resilience from the bounded leakage-resilient cryptosystem by performing an additional key update algorithm while the public parameters keep unchanged. To construct a continuous leakage-resilient cryptography scheme, a new primitive, called it updatable identity-based hash proof system (U-IB-HPS), is proposed, which is an improved IB-HPS. In particular, the improved system has an additional key update algorithm, which can push some new randomness into the private key of user (or the master secret key), the updated results are random in the adversary's view, and the leakage of previous private key of user (or the master secret key) does not work for the updated results. However, the previous instantiations of U-IB-HPS cannot achieve the claimed security. To solve the above problems, in this paper, two instantiations of U-IB-HPS with better performance are created, and the security of proposed system is proved, in the standard model, based on the classic decisional bilinear Diffie-Hellman assumption. The corresponding IBE scheme created with our U-IB-HPS allows continuous leakage of multiple keys, i.e., continuous leakage of the master secret key and the private key of user. Additionally, our U-IB-HPS can also be employed as an underlying basic tool to build the generic construction of continuous leakage-amplified public-key encryption scheme, continuous leakage-resilient identity-based authenticated key exchange protocol, and continuous leakage-resilient public-key encryption scheme with keyword search, etc. [ABSTRACT FROM AUTHOR]

Modular multiplication plays a crucial role in modern cryptography. Montgomery modular multiplication(MMM), one of the most classic and practical modular multiplication algorithms, has been widely used in cryptographic algorithms such as RSA, Diffie–Hellman algorithm, and Elliptic Curve Cryptography. In this paper, we incorporate negative wrapped convolution (NWC) into the FFT-based Montgomery modular multiplication to avoid the issue of zero-padding and use carry-save arithmetics for parallel computation. By utilizing coefficient pairs (pos_part and neg_part), we reconstruct the final result and eliminate the restrictions imposed by nega-cyclic parts. Moreover, Karatsuba-like algorithm is introduced for building fine-grained large integer multipliers. We have modified the parameter specifications for our design to meet requirements from diverse application scenarios. We implement the design on Xilinx Virtex-7 FPGA under different conditions and compare the results with the state-of-the-art MMM designs. The comparisons confirm that our design has the following characteristics: low latency for process, competitive area-latency-product(ALP), efficient DSP usage, and constant delay, which enhances security against timing attacks. • Montgomery Modular Multiplication. • Parallel Computation. • Hardware Acceleration. [ABSTRACT FROM AUTHOR]

Attribute-based encryption with keyword search (ABKS) is a versatile public-key encryption system that supports access control and ciphertext retrieval. However, it often involves complex computations for ciphertext generation. To overcome this challenge, researchers have proposed several online/offline ABKS (OOABKS) schemes. These schemes optimize online ciphertext generation by pre-generating intermediate ciphertexts in an offline manner. However, we find some limitations of existing OOABKS schemes: (1) Some schemes lack flexibility because the intermediate ciphertext is embedded with an access structure and therefore it cannot be used to generate a final ciphertext encrypted under another access structure. (2) Other schemes fail to achieve the basic security requirement. In this work, we conduct a comprehensive analysis of existing OOABKS schemes. Next, we propose a revised OOABKS scheme that offers provable security based on the well-known Bethencourt et al.'s attribute-based encryption scheme. Our scheme retains the advantages of online/offline ciphertext generation in previous OOAKBS schemes while addressing their limitations. Experiment results show that our revised scheme achieves comparable efficiency to previous OOABKS schemes without sacrificing flexibility or security. [ABSTRACT FROM AUTHOR]

Ghost imaging technology has been widely used in the field of optical image encryption owing to its unique non-local imaging characteristics. However, there are some problems such as long encryption and decrypting time, poor reliability and large number of keys. To solve these problems, this paper proposed a computational ghost imaging encryption scheme based on RSA algorithm and wavelet transform. Firstly, the representation relationship between measurement matrix and random integer sequence is established to reduce the transmission of key quantity. Secondly, RSA encryption algorithm is used to improve the security of the system. Finally, using wavelet decomposition for packet transmission. In addition, the cake cutting matrix is used as the measurement matrix to reduce the sampling times and improve the quality of reconstructed images. The simulation results show that the encryption system has strong information transmission security and good robustness. It provides some reference for image encryption and information security transmission. • First: Proposed an optical image encryption scheme based on computational ghost imaging. • Second: The encryption process uses improved RSA encryption algorithm and wavelet transform. • Third: The results show that the scheme has good safety and noise resistance. [ABSTRACT FROM AUTHOR]

In the situation where there are one sender and multiple receivers and the sender transmits ciphertexts of correlated plaintexts, a receiver selective opening (RSO) attack for a public key encryption (PKE) scheme considers adversaries that can corrupt some of the receivers and get their secret keys and plaintexts. Security against RSO attacks for a PKE scheme ensures confidentiality of ciphertexts of uncorrupted receivers. Simulation-based RSO security against chosen ciphertext attacks (SIM-RSO-CCA) is the strongest security notion in all RSO attack scenarios. Jia, Lu, and Li (2016) [19] proposed the first SIM-RSO-CCA secure PKE scheme. However, their scheme used indistinguishability obfuscation, which is not known to be constructed from any standard computational assumption. In this paper, we give two contributions for constructing SIM-RSO-CCA secure PKE from standard computational assumptions. Firstly, we propose a generic construction of SIM-RSO-CCA secure PKE using an IND-CPA secure PKE scheme and a non-interactive zero-knowledge proof system satisfying one-time simulation soundness. Secondly, we propose an efficient and concrete construction of SIM-RSO-CCA secure PKE based on the decisional Diffie-Hellman (DDH) assumption. Moreover, we give a method for efficiently expanding the plaintext space of the DDH-based construction. By applying this method to the construction, we obtain the first DDH-based SIM-RSO-CCA secure PKE scheme supporting a super-polynomially large plaintext space with compact ciphertexts. [ABSTRACT FROM AUTHOR]

Structure-preserving primitives are important building blocks in cryptographic protocols. Up to now, the only structure-preserving public-key encryption (SP-PKE) with CCA security over asymmetric pairing groups is based on the SXDH assumption, due to Libert et al. [18]. In this work, we propose a general framework of constructing SP-PKE with leakage-resilient CCA security (which implies the IND-CCA2 security). The corresponding instantiations result in the first leakage-resilient CCA secure SP-PKE from the Matrix Decision Diffie-Hellman (MDDH) assumption (including the SXDH and k -Linear assumptions) over asymmetric pairing groups. The ciphertext of our SP-PKE also enjoys the publicly verifiable property. [ABSTRACT FROM AUTHOR]

• This paper proposes an encryption scheme based on an improved chaotic system that can hide key information. First, we use the RSA algorithm to calculate the parameters of the improved coupled map lattice (CML) system as well as the initial values and the control parameters of the logistics map and the Chebyshev polynomial, respectively. • Then, we obtain a pseudorandom sequence of CML as the key for a one-time pad. Second, we extract the key information from the original image and perform pixel-level diffusion and confusion using different parameters on key and nonkey information based on the pseudorandom sequence generated by the CML system and the sorting function. • In the diffusion step, different diffusion modes are used to ensure that the diffusion effect is not repeated. This paper proposes an encryption scheme based on an improved chaotic system that can hide key information. First, the CML chaotic map is improved, and the chaotic state can be entered from 0. The image of the person is divided into key information and non-key information and spread by different diffusion methods. The RSA algorithm is used to encrypt the size of the key information as part of the key to enhancing the resistance to the chosen plaintext attack. Scrambling is performed at the pixel level using a CML system with a sorting function. The experimental and security analysis results show that the new algorithm has a large key space, is sensitive to keys and plaintext images, has a good encryption effect, and can resist common attack methods. [ABSTRACT FROM AUTHOR]

• An optical image compression and encryption scheme based on compressive sensing and RSA algorithm is proposed. • The Walsh-Hadamard transform and the measurement matrix based on chaotic system are employed to measure the original image. • A pixel scrambling algorithm and the DNA sequence operations are adopted to confuse and diffuse the measurements, respectively. • The RSA algorithm is utilized to encrypt the keys used to enhance the image security during transmission. Most of the image encryption algorithms are the private-key cryptosystem, in which the encryption process and the decryption process employ the same keys. To enhance the security of image encryption system, an optical image compression and encryption scheme based on compressive sensing and RSA public-key cryptographic algorithm is proposed, where the optical compressive imaging system is utilized to sample the original image. In the encryption process, the Walsh-Hadamard transform and a measurement matrix are adopted to simulate the optical compressive imaging system to measure the original image, which can effectively reduce the redundant information in the original image. Then the pixel positions of the resulting image are scrambled with pseudorandom sequence generated by one-dimensional (1D) cascade chaotic system. Furthermore, deoxyribonucleic acid (DNA) sequence operations are exploited to change the pixel values. The keys used in the scheme are generated based on the original image and are protected by the RSA algorithm. Experimental results demonstrate the effectiveness and reliability of the proposed optical image compression and encryption scheme with considerable compression and security performance. [ABSTRACT FROM AUTHOR]

Efficient hardware implementations of public-key cryptosystems have been gaining interest in the past few decades. To achieve the goal, a high frequency as well as low latency Rivest-Shamir-Adleman (RSA) cryptosystem is reported in this paper. To configure such cryptosystem shift-add multiplier have been re-constructed and binary digit based modular exponentiation circuitry is proposed. Such exponentiation circuitry has been implemented through binary bit distribution technique, where, most significant bit (MSB) has been discarded for the implementation, owing to increase the operating frequency. The functionality of the reported algorithms were justified and compared in Hardware Description Language (HDL), simulated in Modelsim and synthesized in Xilinx ISE 14.2 platform. The proposed hardware implementation of RSA algorithm has a maximum frequency of operation of 545 MHz and 298 MHz for the bit sizes of 8 and 64 respectively. The proposed method shows improvements in terms of speed as well as in number of Look-up-tables (LUTs). Moreover, application-specific integrated circuit (ASIC) implementation of such cryptosystem of RSA was carried out through Encounter® RTL Compiler v11.10-p005_1 of Cadence® tool. [ABSTRACT FROM AUTHOR]

The problem of unauthorized access to various content is an important task for the present. It becomes even more acute when using the existing toolkit for the processing and transmission of encrypted images with the fluctuation intensity function. The authors developed a modification of the RSA algorithm to use it in relation to the above-mentioned images. It is proposed a conceptual view for the joint use of quaternary fractional-linear transformations with elements of the basic RSA algorithm. The application of this mathematical apparatus in the basic RSA algorithm avoids contours of image objects in an encrypted sample. In addition, this combination provides additional stability to the basic RSA algorithm for unauthorized decryption. The simulation of the method was carried out in two described by the authors algorithms: using one line and four lines of the image matrix, for grayscale and color images. The high efficiency of the developed method for avoiding contours of objects on encrypted images has been confirmed. In both cases, contours after applying encryption procedures do not appear. The reverse procedure allows to get an image without visible distortion. [ABSTRACT FROM AUTHOR]

Information protection services based on the use of elements of the RSA algorithm are quite reliable because the cryptostability of this method is high (RSA keys from 2048 bits and more). However, in terms of image encryption, in some cases, this algorithm leaves outlines of objects in an encrypted image. This imposes a number of additional limitations on the application of this algorithm. Avoiding partially saving contours in encryption using RSA can be by splitting the initial image into parts so that the image coating is topologically locally finite, that is, compact. The paper proposes a method of encryption-decryption using elements of the RSA algorithm and the topological image coverage. Such a combination will provide both a avoiding of the aforementioned disadvantage and an additional increase in cryptostability. The simulation of the method was done on grayscale and color images using two developed algorithms. The absence of contours of objects of input images in encrypted images of both types is experimentally established. The proposed solution can be used for any type of image, but the greatest benefits are achieved when using images with fluctuation intensity function. [ABSTRACT FROM AUTHOR]

Modular exponentiation is an exponentiation performed over a modulus. It is useful in computer science, especially in the field of public-key cryptography. Most technological applications of modular arithmetic involve exponentials with very large numbers. In this paper, we propose a high radix reconfigurable implementation for the Right-to-Left Modular Exponentiation with NAF-Representation by exploiting the maximum possible parallelism of the internal operations. The proposed design targeted the ALTERA Cyclone IV FPGA (EP4CGX22CF19C7) along with Quartus II simulation package. The proposed design was evaluated in terms of the maximum operational frequency, the total path delay, the total design area and the total thermal power dissipation. The synthesized results revealed that the proposed high radix architecture implementation has recorded: critical path delay of 25.5 ns, maximum operational frequency of 44.59 MHz, hardware design area (number of logic elements) of 2556 LEs, and total thermal power dissipation estimated as 221.82 mW. Consequently, the proposed modular exponentiation architecture can be efficiently employed by many public key cryptographic mechanisms. [ABSTRACT FROM AUTHOR]

A new conceptual scheme of encryption-decryption of grayscale and color images is proposed. It is based on the combining use of elements of the RSA algorithm and projective transformations. Application of the latter in the proposed scheme further increases the cryptographic stability of the method. The algorithmic implementations of the method developed on the basis of the proposed scheme for both element-by-element and for two-element image encryption-decryption is presented. The simulation of the method was carried out using algorithms of element-by-element and two-element encryption-decryption of grayscale and color images. It is established that encrypted images do not have contours of the original images, which provides the requirements for encryption. In addition, the effectiveness of the decryption procedure, where the resulting images haven't visible defects, is confirmed experimentally. [ABSTRACT FROM AUTHOR]

An elastic light-trail, the advanced version of a traditional light-trail, is one of the most recent dynamic traffic grooming technologies in an elastic optical network. In such networks, Orthogonal Frequency Division Multiplexing (OFDM) is a promising technology to execute the RSA (routing and spectrum assignment) algorithm and implement an elastic light-trail as a result. However, the reconfigurable optical add-drop multiplexers (ROADMs) and bandwidth variable Wavelength Selective Switches (WSSs) are required to implement an optically switched and spectrum varying elastic lightpath. In addition to the hardware equipment mentioned above, Add Drop Couplers (ADC) and optical ON/OFF switches (OS) are required to facilitate elastic light-trail in an elastic optical network. Hereafter, deployment of Add Drop Couplers (ADC) and optical ON/OFF switches incurs a significant network cost to facilitate elastic light-trail implementation. Toward the approach for eliminating this costly hardware setup, we have highlighted the fragmentation problem that occurs in spectrum domain in an optical fiber link. In this problem, the entire spectrum range in an elastic optical link is fragmented into several non-contiguous free spectrum slots at an instance during a data transportation session. In this regard, we have proposed "Multiple multi-hop non-contiguous elastic lightpath - MMNCEL " algorithm, where the required spectrum B of a traffic demand r (s , d , B , T) is sliced into n distinct granular spectrums { b 1 , b 2 , ... b n } according to the current availability and status of fragmented spectrum slots in an elastic optical link. Moreover, to setup an elastic lightpath, the algorithm allocates the same range of spectrum from every optical link in a route to preserve Spectrum Continuity Constraint (SCC), whereas, at each hop in a multi-hop elastic lightpath the algorithm performs opto - electrical conversion. In this paper, our objective is to achieve maximum network throughput in an elastic optical network without deploying ADC and optical ON/OFF switches. However, in this work, we have investigated optical spectrum utilization efficiency for the proposed MMNCEL , existing elastic light-trail (Multi-hop Elastic Light-trail algorithm - MELT) and elastic lightpath (Multi-hop elastic Lightpath algorithm - MEL), and performed comparison measurements preciously. [ABSTRACT FROM AUTHOR]

• EAACK has been presented to detection of forged acknowledgement. • P2P ACK, RSA method has been used in this to reduce the routing overhead. • Security level of data transmission has been increased using the RSA public key cryptography. • High level of packet delivery ratio. MANET – Mobile Adhoc Network is a self-configuring network that connected by the number of mobile nodes with wireless links and it has no fixed infrastructure. In this, each single node can operates as both a transmitter and receiver. It has been exploited in various applications such as disaster stuck areas, military, emergency revival etc. Nevertheless, the open intermediate and broad distribution of nodes in MANET can cause a vulnerable to different malicious attacks and MANET that can operate consistently even in the being there of inside packet drop attackers can be really challenging. Therefore, we need to develop Intrusion Detection System to detect the misbehavior nodes during the packet delivery with acknowledgement for the protection of MANET. In this paper, EAACK (Enhanced Adaptive Acknowledgment) is developed with Enhanced Interior Gateway Routing Protocol (EIGRP) hybrid protocol which consists of P2P ACK and RSA algorithm. At present, the network overhead is caused by the digital signature algorithm if more misbehavior nodes are presented on network. Hence, this proposed system is applied with EIGRP to reduce the network overhead caused by digital signatures in EAACK, and P2P (peer-peer) ACK and RSA (named after Ron Rivest, Adi Shamir and Len Adleman) provides more security to the network. S-ACK (Selective Acknowledgements) cannot differentiate the particular node is malicious node. Therefore, this proposed system introduces the P2P ACK to detect the misbehavior node efficiently. Here, RSA can encrypt the session key that creates the key more secure to improve the security level and P2P ACK use this encrypted key for the acknowledgement. In the P2P ACK, keys are generated by the RSA and distributed for signing and verifying the acknowledgement packets in advance. This proposed P2P ACK is used to enhance the detection of misbehavior nodes. The performance of this proposed method can improve the security level and reduce the routing overhead through the secured acknowledgement. [ABSTRACT FROM AUTHOR]

Background: Risk-sharing arrangements (RSAs) can be used to mitigate uncertainty about the value of a drug by sharing the financial risk between payer and pharmaceutical company. We evaluated the projected impact of alternative RSAs for non-small cell lung cancer (NSCLC) therapies based on real-world data.Methods: Data on treatment patterns of Dutch NSCLC patients from four different hospitals were used to perform "what-if" analyses, evaluating the costs and benefits likely associated with various RSAs. In the scenarios, drug costs or refunds were based on response evaluation criteria in solid tumors (RECIST) response, survival compared to the pivotal trial, treatment duration, or a fixed cost per patient. Analyses were done for erlotinib, gemcitabine/cisplatin, and pemetrexed/platinum for metastatic NSCLC, and gemcitabine/cisplatin, pemetrexed/cisplatin, and vinorelbine/cisplatin for nonmetastatic NSCLC.Results: Money-back guarantees led to moderate cost reductions to the payer. For conditional treatment continuation schemes, costs and outcomes associated with the different treatments were dispersed. When price was linked to the outcome, the payer's drug costs reduced by 2.5% to 26.7%. Discounted treatment initiation schemes yielded large cost reductions. Utilization caps mainly reduced the costs of erlotinib treatment (by 16%). Given a fixed cost per patient based on projected average use of the drug, risk sharing was unfavorable to the payer because of the lower than projected use. The impact of RSAs on a national scale was dispersed.Conclusions: For erlotinib and pemetrexed/platinum, large cost reductions were observed with risk sharing. RSAs can mitigate uncertainty around the incremental cost-effectiveness or budget impact of drugs, but only when the type of arrangement matches the setting and type of uncertainty. [ABSTRACT FROM AUTHOR]

Abstract Thus far, several lattice-based algorithms for partial key exposure attacks on RSA, i.e., given the most/least significant bits (MSBs/LSBs) of a secret exponent d and factoring an RSA modulus N , have been proposed such as Blömer and May (Crypto'03), Ernst et al. (Eurocrypt'05), and Aono (PKC'09). Due to Boneh and Durfee's small secret exponent attack, partial key exposure attacks should always work for d < N 0.292 even without any partial information. However, it was difficult task to make use of the given partial information without losing the quality of Boneh–Durfee's attack. In particular, known partial key exposure attacks fail to work for d < N 0.292 with only few partial information. Such unnatural situation stems from the fact that the additional information makes underlying modular equations involved. In this paper, we propose improved attacks when a secret exponent d is small. Our attacks are better than all known previous attacks in the sense that our attacks require less partial information. Specifically, our attack is better than all known ones for d < N 0.5625 and d < N 0.368 with the MSBs and the LSBs, respectively. Furthermore, our attacks fully cover the Boneh–Durfee bound, i.e., they always work for d < N 0.292. At a high level, we obtain the improved attacks by fully utilizing unraveled linearization technique proposed by Herrmann and May (Asiacrypt'09). Although Herrmann and May (PKC'10) already applied the technique to Boneh–Durfee's attack, we show elegant and impressive extensions to capture partial key exposure attacks. More concretely, we construct structured triangular matrices that enable us to recover more useful algebraic structures of underlying modular polynomials. We embed the given MSBs/LSBs to the recovered algebraic structures and construct our partial key exposure attacks. In this full version, we provide overviews and explicit proofs of the triangular matrix constructions. We believe that the additional explanations help readers to understand our techniques. [ABSTRACT FROM AUTHOR]

The battery electric vehicle's (BEV's) stepped automatic transmission (SAT) has a significant influence on the power and economic performance of the new-energy vehicle system dynamics. The SAT entails a complex design process, where the transmission ratio parameter and the control strategy are interactively coupled, causing a difficulty in achieving a globally optimal solution. The actual design process involves multiple design objectives and incurs high design costs. The purpose of this study is to explore the variation characteristics of the design objectives of BEV's SAT and propose a transmission parameter optimization design method with reduced design costs. The paper investigates the interactive coupling property of the transmission ratio parameter and the control strategy, analyzing the high nonlinearity of SAT design objectives using the example of two-gear transmission. It proposes a design method that combines a heuristic optimization algorithm and an estimation model (Method Ⅲ), and a design method that utilizes an improved simulated annealing algorithm and a region search algorithm (ISA-RSA, Method Ⅳ). These methods are compared with a design method based on combination tests using the traversing method (Method Ⅰ) and a design method based on the heuristic optimization algorithm (Method Ⅱ). The results indicate that Method I incurs high design costs with limited effectiveness, while Method II exhibits unstable economic performance and integrated design objectives with fluctuations. Method III is highly dependent on the accuracy of the estimated model and performs poorly in optimizing acceleration time. However, Method Ⅳ, with low design costs, demonstrates remarkable optimization ability to solve high nonlinearity problems and exhibits a high probability of converging to the area near the globally optimal solution. This paper also aims to provide a direct solution to high design cost and highly nonlinear design objective problems in other engineering fields. • The high nonlinearity of BEV's SAT design objectives was analyzed. • The transmission parameters and the control strategy were designed by interactively coupled. • The optimization design methods of SAT based on ISA, IPSO and IGA were proposed. • The design methods combining the estimation model (RBF-NN\ SR\ CSI) were proposed. • The proposed ISA-RSA design method had a higher optimization ability. [ABSTRACT FROM AUTHOR]

Wind turbines are important for clean electric energy, but the increasing number of end-of-life wind turbine blades has become a hazardous waste problem worldwide. A novel recycling approach based on mechanical grinding and combined with 3D printing techniques is a promising solution that will reduce waste at a low cost while retaining the excellent mechanical properties of recycled fabricated samples. Considering the material structure complexity of 3D printed samples, the Representative Volume Element (RVE) is a promising simulation model. This paper proposes a Modified Random Sequential Adsorption (MRSA) algorithm for the efficient generation of RVEs with hybrid and arbitrary-geometry reinforcements. Compared with the classical RSA algorithm, MRSA is advantageous in fiber intersection computational cost. The error between FEA and experiments is lower than results obtained from Mori-Tanaka and Halpin-Tsai. The effects of fiber content, fiber aspect ratio, fiber orientation and local fiber density are discussed. The model will be helpful for accurately predicting properties of 3D printing materials that use recycled wind turbine waste. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Random non-over lapping aggregates. • Effective elastic properties. • Ellipsoidal periodic microstructures. Abstract This work proposes an extension of the well-known random sequential adsorption (RSA) method in the context of non-overlapping random mono- and polydisperse ellipsoidal inclusions. The algorithm is general and can deal with inclusions of different size, shape and orientation with or without periodic geometrical constraints. Specifically, polydisperse inclusions, which can be in terms of different size, shape, orientation or even material properties, allow for larger volume fractions without the need of additional changes in the main algorithm. Unit-cell computations are performed by using either the fast Fourier transformed-based numerical scheme (FFT) or the finite element method (FEM) to estimate the effective elastic properties of voided particulate microstructures. We observe that an isotropic overall response is very difficult to obtain for random distributions of spheroidal inclusions with high aspect ratio. In particular, a substantial increase (or decrease) of the aspect ratio of the voids leads to a markedly anisotropic response of the porous material, which is intrinsic of the RSA construction. The numerical estimates are probed by analytical Hashin-Shtrikman-Willis (HSW) estimates and bounds. [ABSTRACT FROM AUTHOR]

A fast Montgomery multiplier design utilizing the DSP resources in modern FPGAs is presented. In the proposed design, the operand size is the multiples of 528 bits and the digit size is 48 bits. The design has 48  ×  48 bit digit multipliers built from the DSP slices performing 24  ×  16 bit multiplications and a carry select accumulator built from the DSP slices performing 48 bit additions. The proposed Montgomery multiplier works iteratively. In each iteration, a digit of an operand is multiplied by the digits of the other, the result is accumulated, and reduced by Montgomery method. An iteration takes not one but eight cycles to keep the digit multiplier count low and save some hardware resources. The proposed design is implemented for Virtex-7 FPGAs. The performance results are comparable with the best results in the literature. Substantial savings in FPGA logic resources are obtained. [ABSTRACT FROM AUTHOR]

Chaotic synchronization has suffered from demodulating information by hackers via the public channel. Different methods have been developed to hide the contents of a message using chaotic signals. Nevertheless, many studies have shown that most of the existing methods are unreliable in the aspect of security. According to the above, in order to enhance the strength of the cryptosystem and provide greater security, we carry out double encryption which combines chaotic synchronization with RSA algorithm. In this study, a design methodology for neural-network (NN)-based secure communications in multiple time-delay chaotic (MTDC) systems is proposed to obtain double encryption via RSA algorithm and chaotic synchronization. RSA algorithm is an asymmetric encryption and its strength is based on the tremendous difficulty of factorizing two large prime numbers. Accordingly, it takes much more time to process RSA algorithm if the length of the key is much longer. A shorter key is used to decrease the processing time of RSA algorithm in this work. Nevertheless, it will result in a lower security of the cryptosystem. In order to enhance the strength of the cryptosystem, we carry out double encryption which combines chaotic synchronization with RSA algorithm. Moreover, an IGA is proposed in this study to effectively overcome the weakness of the traditional GA. On the basis of the IGA, a fuzzy controller is synthesized to not only realize the exponential synchronization, but also achieve optimal H ∞ performance by minimizing the disturbances attenuation level. Finally, a numerical example with simulations is given to illustrate the effectiveness of our approach. [ABSTRACT FROM AUTHOR]

In order to resolve the key escrow in identity-based scheme and the significant cost of using a PKI system in traditional public key scheme, the notion of certificateless public key cryptography (CL-PKC) was introduced. The first certificateless public key encryption scheme (CL-PKE) was proposed by Al-Riyami and Paterson, and then further schemes were developed. However, most of them are constructed from the bilinear pairing which is a time costing operation. In this paper, we construct an efficient CL-PKE scheme from RSA since RSA is the de facto Internet standard and is widely used in many applications. The security is based on Kilian–Petrank’s RSA assumption which is a variant of RSA. [ABSTRACT FROM AUTHOR]