Stream Cipher

Information security is dependent on various access control mechanism governed by cryptography or the art of encryption and decryption. Cryptography is the largely built in computer hardware or in software using various discrete structure. Security is, thus, merging in network with cryptography to provide secure communication between trusted and/or untrusted network. Efficient mechanism of encryption process is a primary method of protecting valuable electronic information. The encryption process also needs to be dynamic in order to face new hazards and advance methods used by cryptanalysts. RC4 is one of the most popular and efficient stream ciphers . Stream ciphers are often used in applications where high speed and low delay are a requirement. This paper proposes to identify the security requirements for data stream systems; according to the increasing order of robustness. Various security circumstances demand various degree of security robustness. This paper suggests to develop a family of cryptographic algorithm based on the RC4 and checks on the performance of each one to analyze the robustness so that the particular algorithm becomes readily applicable to a circumstance. The applicability of algorithm is totally governed by the requirement of robustness for the security concern of the circumstance. The security concern of robustness of circumstances is matched against the designed ciphersuites where such family of algorithms is available. The process of selection of ciphersuites and hence the cryptographic algorithm is automated in order to ensure appropriate circumstantial robustness. This analysis shows that, the full-size RC4 remains secure against known attacks . The family of algorithm considered here is based on RC4. The basic RC4 algorithm and its variants suggested by different authors like RC4 KSA [3], RC4-PRGA are included in the family. In order enhance the degree of security robustness, two new algorithm S-RC4 1 and S-RC4 2 are proposed. Addition of variants of RC4 increases the range of automatic selection ensuring further enhancement in security. RC4 family is analyzed for encryption, decryption and algorithm strength is analyzed. Robustness is determined considering both the factors; speed of encryption/decryption or performance and algorithm strength. It is proposed to evaluate the effect of existing RC4 changing different parameters.

The development of technology at this time allows everyone to exchange information without any limitation of time and distance. The possibility that data leakage will occur during the process of exchanging information is carried out, therefore in sending data especially images, security aspects, confidentiality and efficiency of data storage is very necessary. If the important information falls into the wrong hands, it will cause unwanted things, for example manipulation of images with negative shapes and can harm the owner of the image. One method used to maintain data security is cryptography using one of the techniques, Elgamal. The strength of this algorithm lies in the difficulty of calculating discrete algorithms on prime integers in which multiplication operations are performed. In this research, the writer combines Hill Cipher to do image encryption and Elgamal Algorithm to decrypt the key of Hill Cipher. The image is first encrypted using the Hill Cipher, then the Hill Ciph...

In this paper we describe how to use special induced subgraphs of generalized m-gons to obtain the LDPC error correcting codes. We compare the properties of codes related to the affine parts of q-regular generalised 6-gons with the properties of known LDPC codes corresponding to the graphs D(5, q).

In this paper we investigate correcting properties of LDPC codes obtained from families of algebraic graphs. The graphs considered in this article come from the infinite incidence structure. We describe how to construct these codes, choose the parameters and present several simulations, done by using the MAP decoder. We describe how error correcting properties are dependent on the graph structure. We compare our results with the currently used codes, obtained by Guinand and Lodge from the family of graphs D(k, q), which were constructed by Ustimenko and Lazebnik .

In this paper we present an algorithm to compute keyed hash function (message authentication code MAC). Our approach uses a family of expander graphs of large girth denoted D(n, q), where n is a natural number bigger than one and q is a prime power. Expander graphs are known to have excellent expansion properties and thus they also have very good mixing properties. All requirements for a good MAC are satisfied in our method and a discussion about collisions and preimage resistance is also part of this work. The outputs closely approximate the uniform distribution and the results we get are indistinguishable from random sequences of bits. Exact formulas for timing are given in term of number of operations per bit of input. Based on the tests, our method for implementing DMAC shows good efficiency in comparison to other techniques. 4 operations per bit of input can be achieved. The algorithm is very flexible and it works with messages of any length. Many existing algorithms output a fixed length tag, while our constructions allow generation of an arbitrary length output, which is a big advantage.

The problem of searching for aperiodic binary sequences with high entropy and uniform element distribution presents significant computational complexity, particularly as the sequence length increases. Such sequences are of crucial importance in communication engineering, radar systems[4], spectroscopy, quantum physics, chemistry, digital signal processing, and cryptography [3]. This paper examines the possibility of employing generators based on Galois fields, in particular linear feedback shift registers in Galois configuration (Galois LFSR), for constructing binary pseudorandom sequences and evaluating their entropic characteristics. A brief overview of the algebraic foundations of sequence generation in finite fields GF(2) through primitive polynomials is provided [2]. The obtained results can be applied to the design of signals with defined statistical properties, including high information density, which is critically important for spread spectrum systems and cryptographic protocols.

The paper presents a detailed analysis of two types of pseudorandom binary sequence generators obtained by using tent map. The test is performed using a NIST statistical test suite which is widely used for testing the randomness of any random number generator. The binary sequences under investigation are obtained either by considering all the successive iterations of the tent map and choosing a threshold equal to the tent map parameter or by applying a periodical sampling on the tent map values and by choosing a threshold equal to 0.5. Additionally, the paper comes up with a new discussion concerning the elements of the secret key for both of the generators. Based upon the results presented in the paper, both generators can be used for designing a new cipher where the pseudorandom binary sequence is the main ingredient of the cipher.

RF TEMPEST attacks, as a subset of side-channel attacks, i.e. wireless eavesdropping on unwanted residual RF signals emanating from electronic devices (with the intention to steal secret data) have been around since 1916. Many electronic devices, analogue (wired analogue telephone, tape recorders, CRT monitors, etc.) and digital (LCD monitors, keyboards, printers, CPUs, memory ICs, etc.) have been attacked since then. Microgrid power converters, especially those attending large lithium battery banks, have recently become a preferred target for malicious attacks. RF signals from these devices can be received, amplified, demodulated, decoded, and then decrypted. Security-critical data (e.g., private encryption keys and passwords) is thus stolen, and security is compromised. Encryption doesn't help here, it can be bypassed, because the secret data is stolen while being processed in its plaintext form. Wireless eavesdropping on a higher UHF harmonic of a CPU clock generator can reveal the data currently being processed inside the CPU. A method of protection is devised by a hardware add-on to the CPU clock, based on a true-random number/electronic noise generator. Its operation is first confirmed by LTSpice simulation and then by tests performed on the assembled perfboard prototype.

In this paper, we construct a fully homomorphic encryption (FHE) scheme over integers with the message space Z Q for any prime Q. Even for the binary case Q = 2, our decryption circuit has a smaller degree than that of the previous scheme; the multiplicative degree is reduced from O(λ(log λ) 2 ) to O(λ), where λ is the security parameter. We also extend our FHE scheme to a batch FHE scheme.

En el año 2012 la International Organization for Standardization (ISO) y la International Electrotechnical Commission (IEC) han publicado la norma ISO/IEC 29192-3:2012. En ella se especifican dos algoritmos de cifrado de flujo para ser utilizados en criptografía liviana: el Enocoro y el Trivium. En el caso del Trivium quedan por resolver aún algunos problemas abiertos: no se conoce la forma de determinar la longitud de recursión de las secuencias seudoaleatorias que genera tampoco su período, se desconoce la existencia de ciclos cortos y cuáles son los estados iniciales que los generan (claves débiles).

The paper presents a new approach for triple key generation techniques with Henon, Lozi and Duffing chaotic maps in FPGA. Three key streams generated by XORing chaotic maps with pseudo random number generators, the results of XORing PN1 with PN2 is called gold code generator. The algorithm was built in embedded Xilinx System Generator tool (XSG) and the results were validated using MATLAB/SIMULINK environment. NIST, Normality and Dieharder test randomness tests were employed for key streams and verified as the best randomness in comparison with recent work.

Optimization remains a cornerstone of modern engineering and computational intelligence, playing a vital role in the design, control, and allocation of limited resources across industries ranging from logistics to structural engineering. Traditional optimization methods, such as gradient-based and exact algorithms, often struggle with the nonlinear, multimodal, and constrained nature of real-world problems, necessitating the adoption of metaheuristic approaches. These biologically and physically inspired algorithms offer flexibility, scalability, and robustness in navigating complex search spaces. This study presents a systematic categorization of optimization problems-including combinatorial, continuous, constrained, and multiobjective classes-followed by a rigorous comparative analysis of nine prominent metaheuristics: Ant Colony Optimization (ACO), Lion Algorithm (LA), Cuckoo Search (CS), Grey Wolf Optimizer (GWO), Vibrating Particles System (VPS), Social Spider Optimization (SSO), Cat Swarm Optimization (CSO), Bat Algorithm (BA), and Artificial Bee Colony (ABC). The algorithms are evaluated across five representative benchmark problems: the Traveling Salesman Problem (TSP), Welded Beam Design (WBD), Pressure Vessel Design (PVD), Tension/Compression Spring Design (TSD), and the Knapsack Problem (KP). Key contributions include: 1)Domain-specific suitability analysis, revealing how algorithmic mechanisms align with problem structures. 2) Performance benchmarking under standardized conditions, highlighting convergence speed, solution quality, and constraint-handling efficacy. 3) Practical insights for practitioners on algorithm selection, hybridization potential, and adaptation challenges. Results demonstrate that no single algorithm dominates universally; instead, problem characteristics dictate optimal choices. For instance, ACO excels in discrete problems (TSP, KP), while GWO and BA outperform in continuous engineering designs (WBD, PVD). The study concludes with recommendations for future research, including dynamic parameter tuning, hybrid models, and real-world scalability assessments.

While the A5/1 stream cipher encryption is known to aid in providing security and privacy for the mobile communication, it actually has numerous security vulnerabilities that leave it susceptible to attacks. Although newer technology standards have been developed, the majority of the mobile phones around the world still make use of the A5/1 stream cipher design, hence the urgent need to strengthen the latter. Numerous works have been done to improve the security of the A5/1, such as by altering its clocking mechanism, and the length of the linear feedback shift register, leading to the ultimate goal of producing a stream of random bits which are difficult to crack, with the National Institute of Standards and Technology (NIST) Statistical Toolsuite used to analyse the randomness property of the results. However, none of them, to the best of the author's knowledge actually carried out the analysis of the results according to the guideline as per recommended by the NIST, despite the fact that the interpretation of the results is crucial in determining the strength of the stream cipher, as to whether it is robust to attacks, or otherwise. In this paper, a new modified A5/1 stream cipher is proposed and tested using the NIST test suite. The results, interpreted according to the NIST guidelines, by analysing the proportion of sequences passing test and the uniformity of the P-value, shows that the new modified design is random and is a good alternative to the conventional A5/1 stream cipher. A selective review of the weaknesses of a few of the interpretations by the other researchers will also be included.

Chaos has suggested some new and efficient way to develop image encryption technique. It is because chaos has a chaotic random characteristic. Therefore chaos often is used as a random generator in image encryption and decryption. One of the chaos functions is logistic map. The logistic map is a polynomial mapping of degree 2, often cited as an example of how complex chaotic behavior can arise from very simple non-linear dynamical equations. The aim of this research is to implement image cryptosystems using chaos technique combined with stream cipher method, feedback function and 256-bit of external key. In stream cipher, chaos technique is used to replace key stream generator to produce random seed. The feedback function is to encrypt with previous plain image. The use of 256-bit external key can be represented as 32 characters in ASCII. The results of testing show that the size of the file don't change before and after encryption and decryption process, there's time difference between encrypt and decrypt process and also different key can influence the output of encryption process.

The first part of this paper considers the diamond structures which were first introduced and applied in the herding attack by Kelsey and Kohno . We present a new method for the construction of a diamond structure with 2 d chaining values the message complexity of which is O(2 n+d 2 ) . Here n is the length of the compression function used. The aforementioned complexity was (with intuitive reasoning) suggested to be true in and later disputed by Blackburn et al. in [3]. In the second part of our paper we give new, efficient variants for the two types of Trojan message attacks against Merkle-Damgård hash functions presented by Andreeva et al. [1] The message complexities of the Collision Trojan Attack and the stronger Herding Trojan Attack in [1] are O(2 n 2 +r ) and O(2 2n 3 + 2 n 2 +r ) , respectively. Our variants of the above two attack types are the Weak Trojan Attack and the Strong Trojan Attack having the complexities O(2 n+r 2 ) and O(2 2n-s 3 + 2 n+r 2 ) , respectively. Here 2 r is the cardinality of the prefix set and 2 s is the length of the Trojan message in the Strong Trojan Attack.

This paper proposes a Driverless Intelligent Vehicle that has an onboard GPS equipped autopilot system, which is capable of driving the vehicle from one point to another without human operator and also with a theft control system for an automobile, which is being used to prevent/control the theft of a vehicle. The developed system makes use of an embedded system based on GSM technology. The designed and developed system is installed in the vehicle. An interfacing mobile is also connected to the microcontroller, which is in turn, connected to the engine. Once, the vehicle is being stolen, alert SMS will be sent to the vehicle owner for further processing. By reading the SMS received by the mobile, one can control the ignition of the engine; say to lock it or to stop the engine immediately. Again it will come to the normal condition only after entering a secured password. The owner of the vehicle and the central processing system only know this secured password. When the vehicle is st...

Cryptographic protocols with adaptive security ensure that security holds against an adversary who can dynamically determine which parties to corrupt as the protocol progresses-or even after the protocol is finished. In the setting where all parties may potentially be corrupted, and secure erasure is not assumed, it has been a long-standing open question to design secure-computation protocols with adaptive security running in constant rounds. Here, we show a constant-round, universally composable protocol for computing any functionality, tolerating a malicious, adaptive adversary corrupting any number of parties. Interestingly, our protocol can compute all functionalities, not just adaptively well-formed ones. The protocol relies on indistinguishability obfuscation, and assumes a common reference string.

The associated codes of almost perfect nonlinear (APN) functions have been widely studied. In this paper, we consider more generally the codes associated with functions that have differential uniformity at least 4. We emphasize, for such a function F , the role of codewords of weight 3 and 4 and of some cosets of its associated code C F . We give some properties on codes associated with differential uniformity exactly 4. We obtain lower bounds and upper bounds for the numbers of codewords of weight less than 5 of the codes C F . We show that the nonlinearity of F decreases when these numbers increase. We obtain a precise expression to compute these numbers, when F is a plateaued or a differentially two-valued function. As an application, we propose a method to construct differentially 4-uniform functions, with a large number of 2-to-1 derivatives, from APN functions.

This paper shows that Physics is very close to the substitution-diffusion paradigm of symmetric ciphers. Based on this analogy, we propose a new cryptographic algorithm. Statistical Physics gives design principles to devise fast, scalable and secure encryption systems. In particular, increasing space dimension and considering larger data blocks improve both speed and security, allowing us to reach high throughput (larger than 10Gb/s on dedicated HW). The physical approach enlarges the way to look at cryptography and is expected to bring new tools and concepts to better understand and quantify security aspects.

Cryptography is a science concerned with securing data transmission. By applying cryptographic operations to data, readable information is converted into unreadable data. Currently, security is of great importance. Data transferred over the internet must have some form of encryption. Different forms of multimedia contents are moved over the internet. This paper focuses on image encryption. It tries to amend the multiple selective region image cryptography techniques using a RC4 stream cipher. This approach is derived from the standard RC4 algorithm. The proposed method can highly improve security for images transferred over the internet.

Boolean networks are used to model biological networks such as gene regulatory networks. Often Boolean networks show very chaotic behaviour which is sensitive to any small perturbations. In order to reduce the chaotic behaviour and to attain stability in the gene regulatory network, nested Canalizing Functions (NCFs) are best suited. NCFs and its variants have a wide range of applications in systems biology. Previously, many works were done on the application of canalizing functions, but there were fewer methods to check if any arbitrary Boolean function is canalizing or not. In this paper, by using Karnaugh Map this problem is solved and also it has been shown that when the canalizing functions of n variable is given, all the canalizing functions of 1  n variable could be generated by the method of concatenation. In this paper we have uniquely identified the number of NCFs having a particular Hamming Distance (H.D) generated by each variable i x as starting canalizing input. Partially NCFs of 4 variables has also been studied in this paper.

Due to practical constraints in preventing phishing through public network or insecure communication channels, simple physical unclonable function (PUF)-based authentication protocol with unrestricted queries and transparent responses is vulnerable to modeling and replay attacks. In this paper, we present a PUF-based authentication method to mitigate the practical limitations in applications where a resource-rich server authenticates a device with no strong restriction imposed on the type of PUF designs or any additional protection on the binary channel used for the authentication. Our scheme uses an active deception protocol to prevent machine learning (ML) attacks on a device. The monolithic system makes collection of challenge response pairs (CRPs) easy for model building during enrollment but prohibitively time consuming upon device deployment. A genuine server can perform a mutual authentication with the device at any time with a combined fresh challenge contributed by both the server and the device. The message exchanged in clear does not expose the authentic CRPs. The false PUF multiplexing is fortified against prediction of waiting time by doubling the time penalty for every unsuccessful authentication.

Because of the tremendous rise in internet-based cybercrime, the safety of data is becoming increasingly important in order for the internet to continue providing its many features and benefits. The largest problem for data owners and service providers is ensuring the security and privacy of their data. Digital technology has become an integral element of our daily lives. Technology plays a vital part in everything from online shopping to online banking to government infrastructure. Cyber-attacks, on the other hand, are a blemish on the digital landscape. As a result, the authors devised a new symmetric algorithm that utilizes a private key and delivers a more scalable, secure, and speedy algorithm solution. As a result of this algorithm's efforts, the security hazards to confidential material will be greatly reduced. This study focuses mostly on the issues that data security faces when working with the most current technology.

A proposed stream cipher, RRSC-128AEAD, supports authenticated encryption with associated data (AEAD) for checking both the authenticity and integrity of the message. This cipher includes a key and a nonce of size 128-bit each as input. It produces two different pseudo-random bit streams in parallel. One is used for encryption and another one is used for authentication purposes. It generates 64-bit MAC, based on the National Institute of Standards and Technology standardized (NIST) value, for lightweight security. The cipher efficiency in terms of randomness is analyzed by an online NIST statistical test suite. The design is compared with NIST standardized stream cipher GRAIN-128AEAD. The proposed cipher proves its efficiency in key reintroduction and probability of avoiding key leakage compared to GRAIN-128AEAD. Although both cipher initialization times are the same, some features like two independent bit streams, large internal states, and variable-length associated data and maski...

The focus of this work is to provide authentication and confidentiality of messages in a swift and cost effective manner to suit the fast growing Internet applications. A nested hash function with lower computational and storage demands is designed with a view to providing authentication as also to encrypt the message as well as the hash code using a fast stream cipher MAJE4 with a variable key size of 128-bit or 256-bit for achieving confidentiality. Both nested Hash function and MAJE4 stream cipher algorithm use primitive computational operators commonly found in microprocessors; this makes the method simple and fast to implement both in hardware and software. Since the memory requirement is less, it can be used for handheld devices for security purposes.

A new fast stream cipher, MAJE4 is designed and developed with a variable key size of 128-bit or 256-bit. The randomness property of the stream cipher is analysed by using the statistical tests. The performance evaluation of the stream cipher is done in comparison with another fast stream cipher called JEROBOAM. The focus is to generate a long unpredictable key stream with better performance, which can be used for cryptographic applications. Keywords-cryptography, stream cipher, pseudo random number generator (PRNG)

A novel stream cipher based on the popular linear feedback shift register (LFSR) with a dynamic feedback network controlled by a decoder circuit is presented. The proposed circuit can be employed efficiently in cryptographic applications owing to its improved inviolability property compared to traditional LFSRs. Indeed, although the proposed topology and traditional LFSRs have similar statistical properties, it exhibits a very high linear complexity (LC) and the sequences generated from the novel topology are much more difficult to be predicted. The proposed cipher is described and design criteria to choose the key of the system are also given. As an example, a 16-bit length generator was implemented on a Xilinx FPGA and experimentally verified using the most common statistical and randomness tests. Then it was also designed in standard cell AMS technology. Moreover, to test the generator's inviolability, a novel methodology, based on a multiperceptron neural network, was also developed and is also presented.

At this time the security of communication can be the important role of electronic communication. In this paper we can discuss the new transform for the protection of digital signals using with golden matrix. Fibonacci - Pell (FP) Transform can be find sufficient results to secure the signals and the aims of this paper to describe the security of signals using new type of recurrence formula. The recurrence relation can be find sufficient results to secure the signals. Multiple encryptions are used in this algorithm. Fibonacci - Pell (FP) Transform used for encryption and affine cipher can be used for super encryption. It ensures that to secure the data from attackers in this cryptographic method is fast and simple.

This paper aims at overcoming the shortcomings of RC4 (Rivest Cipher 4) algorithm that mainly resides in the "key scheduling algorithm" (KSA) of RC4. This paper is a trial to enhance key generation of RC4 on the basis of logistic maps with multi-parameters named (EKSA), the permutation of array of S improved to base of the generator for the random numbers that depend on three logistic maps with two parameters, three parameters and four parameters, the suggested algorithm result the follow : outcome = T ⊕ generated key ⊕ value that is random from EKSA (Lm4p (w)) The secrecy is tested for the enhancement RC4 with EKSA, in addition to the arbitrariness and variable key size effectiveness and different size of the plaintext regarding to those of the original RC4.The outputs display that original RC4 with KSA is less powerful than the the enhancement RC 4 with EKSA.

In recent years, because of the frequent flow of digital images across the world over the transmission media, image encryption become one of the most substantial topics. In this paper, we propose a new image encryption method based on the well-known Chaotic Logistic Map (CLM) and the Rivest Cipher 4 (RC4) encryption methods. Here, we use the secret key, and the CLM to produce a one-dimensional array of different numbers. Then the RC4 algorithms used to make some sort of random shuffling (relying on the contents of the array created by the CLM) to the array that is created by the RC4 first algorithm. After that, the second algorithm of RC4 used inside a loop to change the value of each color (using the resultant array of the first RC4 algorithm) of a pixel until all the pixels of the image be changed. And by doing that we have produced a cipher image that is completely different and does not reveal any information of the plain image, also we proved that it is really a key sensitive encryption that can't be decrypted easily by using brute force or any other kind of attacks.

Contemporary data centers implement hybrid storage systems that consist of layers from solid-state drives (SSDs) and hard disk drives (HDDs). Due to their high data retrieval speed, SSDs layer is used to store important data blocks that have features like high frequency of access. To boost their security level, many of such systems implement self-encryption algorithms like advanced encryption standard (AES), Blowfish, and triple data encryption standard (3DES) with different key sizes that vary in their complexity and their decryption latency whenever a block is requested for read. Frequently accessed data blocks with increased decryption latencies are better to be migrated to the SSDs layer to decrease their retrieval latency. In this paper, we introduce a linear complexity algorithm hybrid self-encryption storage data migration (HSESM) that migrates important data blocks that requires long decryption latencies from the HDDs layer to the SSDs one. Performance evaluation shows that HSESM data migration process can reduce data blocks read latencies in 13.71%-23.61% under worst-case scenarios.

In the 4.0 industrial revolution, technologies are designed to be able to connect to the internet. These technologies should be able to exchange data between them using sensors and others. One of the ways to send it is by the wireless sensor network. However, involving the internet in exchanging data needs security guarantees. Three things must meet in network security, that is confidentiality, integrity, and availability. Cryptography use for the confidentiality of the information that will be sent by the user. In this research will be using the symmetric cryptography for network security on wireless sensor networks. In addition to network security, symmetric cryptography method will be used also consider energy efficiency on a wireless sensor network. Chacha stream cipher as symmetric cryptography will be used as a method of messages encryption. Experiments in this research used NS-3 as a network simulator. Results of the tests show that the purpose method has a computation time o...

Impossible-differential cryptanalysis is one of the powerful methods utilized for evaluating the robustness of block ciphers; however, mCrypton is one of the block ciphers whose master key has not been recovered with this method in the single-key scenario. This paper first clarifies the branch number of the linear layer of mCrypton block ciphers with an observation. It has been shown that the branch number of the linear layer in mCrypton block cipher is four. Then, using this result, a 4-round impossible differential in a single-key scenario has been found. On the other hand, by exploiting the result of several observations, some vulnerabilities in the key-schedule algorithm were discovered and introduced. As a result, by exploiting the discovered vulnerabilities and 4-round property, impossible-differential cryptanalysis was successfully applied to seven rounds of mCrypton-64. To our knowledge, this is the first impossible differential cryptanalysis applied on mCrypton-64. In addition, this method requires 2 36.0 bytes of memory, 2 59.0 chosen plaintexts (with the corresponding ciphertexts), and 2 59.6 encryptions to recover the master key.

A smart card is a small pocket-sized computer with limited resources used for secure data processing and storage. The card consists of different software and hardware components, including a microprocessor, crypto co-processor, RAM, secure ROM, and operating system. Even though smart cards have a lot of limitations in terms of processing power and small-sized memory, smart cards are widely used in many applications that require a high degree of security such as e-passports, citizen cards, e-banking, etc... Basically, the security of a smart card depends mainly on the security strength of the cipher algorithm implemented inside. This paper presents a new lightweight, high-speed, and cryptographically strong stream cipher algorithm (ANCHOR) suitable for implementation on smart cards. The building blocks of the proposed cipher were carefully built/chosen with high-valued cryptographic properties. The randomness and linear complexity properties of the proposed cipher algorithm have been successfully tested with statistical tests of the NIST suite and the Berlekamp-Massey algorithm respectively. In order to test the performance of the proposed cipher algorithm, the algorithm was developed in C language and executed on a Linux machine.

Side Channel Attack (SCA) exploits the physical information leakage (such as electromagnetic emanation) from a device that performs some cryptographic operation and poses a serious threat in the present IoT era. In the last couple of decades, there have been a large body of research works dedicated to streamlining/improving the attacks or suggesting novel countermeasures to thwart those attacks. However, a closer inspection reveals that a vast majority of published works in the context of symmetric key cryptography is dedicated to block ciphers (or similar designs). This leaves the problem for the stream ciphers wide open. There are few works here and there, but a generic and systematic framework appears to be missing from the literature. Motivating by this observation, we explore the problem of SCA on stream ciphers with extensive details. Loosely speaking, our work picks up from the recent TCHES’21 paper by Sim, Bhasin and Jap. We present a framework by extending the efficiency of...

Now a days, Hill cipher is almost relegated. It is mostly referred to as a reference or rather history material. This is due to its weaknesses in terms of security, difficulty in both the multiplication and inverse computation of matrices. This paper presents a variant of the Hill Cipher that can be used to encrypt several ciphertexts together via the concept of rhotrices. In the proposed scheme, computation of products and inverses is easier and faster since computing products and inverses of rhotrices using heart based multiplication method is known to be easier than that of matrices. Also each plaintext rhotrix is indirectly encrypted by using its own key since it is presented in a row or column major similar to a plaintext block. Therefore, the presented scheme takes care of some of the drawbacks of the classical Hill cipher.

Information safety plays an important role in modern technologies. A stream encryption is one of the common means for information safety support. The sequences with pseudo-random characteristics are often required in the algorithms of stream enciphering. Random systems are recently used as a source of pseudo-random numbers with desired statistical properties. A small length of a sequence period is one of the known problems of the generators of pseudo-random numbers based on chaos realized with a small length of a digit grid. The disturbance of a path or a parameter of random system nonlinearity is one of possible solutions of a short period problem. In this paper there is considered a new approach to the increase of a period length through the change of a symmetry factor in the random model of a memristive circuit. The approach offered is based on switching two values of the symmetry factor in accordance with the output of a shear register with the linear feedback. To confirm the ef...

SNOW 3G is a synchronous, word-oriented stream cipher used by the 3GPP standards as a confidentiality and integrity algorithms. It is used as first set in long term evolution (LTE) and as a second set in universal mobile telecommunications system (UMTS) networks. The cipher uses 128-bit key and 128 bit IV to produce 32-bit ciphertext. The paper presents two techniques for performance enhancement. The first technique uses novel CLA architecture to minimize the propagation delay of the 232 modulo adders. The second technique uses novel architecture for S-box to minimize the chip area. The presented work uses VHDL language for coding. The same is implemented on the FPGA device Virtex xc5vfx100e manufactured by Xilinx. The presented architecture achieved a maximum frequency of 254.9 MHz and throughput of 7.2235 Gbps.

This paper proposes a novel method of message cryptography aiming to provide a simple, secure, and highly efficient approach to encryption and decryption. Unlike existing methods that rely on complex logical operations, our method utilizes simple rearrangement operations, reducing computational complexity while ensuring robust security. It employs a sophisticated, high-entropy private key designed to withstand hacking attempts. This key generates two chaotic keys using chaotic logistic map models, which are sorted to form two index keys essential for rearranging message blocks and characters during encryption and decryption. The process is facilitated by two simple operations, Get_index and Get_min, based on the index keys. These operations achieve streamlined procedures without compromising security. The method's speed is evaluated across various message lengths, demonstrating significant improvements in encryption time and throughput. The comparative analysis highlights the superior efficiency of this method compared to existing methods. Rigorous testing confirms that the proposed method meets stringent quality and sensitivity requirements, ensuring robust cryptographic standards. This innovative approach offers a promising solution for secure message encryption and decryption, combining simplicity, security and efficiency to meet the evolving needs of secure communication systems.

Fast and secure data stored and transmission through a modern communication and information system are the core objective in this area. With regard to this study, efficient and simple algorithm has been suggested that takes advantage of double piecewise-linear chaotic map method and RC4 algorithm. Each algorithm is utilized as Pseudo Random-Number-Generator (PRNG). The proposed piecewise generator produces series of M × N random sequence keys that are used as an initial key for the RC4 algorithm that has been utilized for generating another M × N key sequence. At each round, an image is converted into onedimension, then the Fisher-Yates Shuffle algorithm has been utilized for achieving confusion operation, controlled by chaotic matrix created by double piecewise algorithm as well as diffusion is achieved by performing a complex (XOR) operation between confused image and matrix generated by RC4 algorithm. The experimental results on speed of encryption/decryption process, keys-pace a...

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The Integer Dichotomy Diagram IDD(n) represents a natural number n ∈ N by a Directed Acyclic Graph in which equal nodes are shared to reduce the size s(n). That IDD also represents some finite set of integers by a Digital Search DAG where equal subsets are shared. The same IDD also represents representing Boolean Functions, IDDs are equivalent to (Zero-suppressed) ZDD or to (Binary Moment) BMD Decision Diagrams. The IDD data-structure and algorithms combines three standard software packages into one: arithmetics, sets and Boolean functions. Unlike the binary length l(n), the IDD size s(n) < l(n) is not monotone in n. Most integers are dense, and s(n) is near l(n). Yet, the IDD size of sparse integers can be arbitrarily smaller. We show that a single IDD software package combines many features from the best known specialized packages for operating on integers, sets, Boolean functions, and more. Over dense structures, the time/space complexity of IDD operations is proportional to t...

Cybersecurity threats are evolving at a very high rate, thus requiring the use of new methods to enhance the encryption of data and the communication process. In this paper, we propose a new key generation algorithm using the simultaneous use of the SqueezeNet deep learning model and hyperchaotic map to improve the hallmark of cryptographic security. The method employed in the proposed approach is built around the SqueezeNet model, which is lighter and faster in extracting features from the input image, and a hyperchaotic map, which is the main source of dynamic and non-trivial keys. The hyperchaotic map enhances complexity and randomness, securing the new cryptosystem against brute force and statistical attacks, and the key length depends on the number of features in the image. All our experiments prove that the proposed key generator works well in generating long, random, high entropy keys and is highly resistant to all typical cryptographic attacks. The promising profound synergy of deep learning and chaotic systems provides directions for the development of secure and effective methods of cryptography amid the exacerbated cyber threats. The technique was found to meet all the 15 criteria as tested through the NIST statistical test suite.

This paper provides novel hardware design for frequency-hopping pseudorandom bit generator (PRBG).PRBG design by chaotic maps on FPGA.Two proposed methods in this work first combine chaotic maps in a cascade manner called fixed point cascade chaotic maps (FPCCM-FHSS), and second, the conjunction of chaotic maps done in an XORed manner called fixed point an XOR chaotic method (FPXORCM-FHSS).The results were the first eight NIST randomness tests.Frequency indicates that all p-values larger than 0.01 are needed to achieve better randomness, Second and third were die-hard tests, many distribution tests with significant p-values (p <0.01) that meet high standards of statistical randomness, making them suitable for channel security.Last were the FPGA results between the proposed methods for speed and hardware resources).The works implemented on XILINX ZC702 achieved 2 Gbps to meet the speed requirements of the change of the carrier frequency.

A Stream Cipher (SC) is a symmetric-key encryption type that scrambles each piece of data in clear text to conceal it from hackers. Despite its advantages, it has a substantial challenge. Correct handwriting of the script code for the cipher scheme is a challenge for programmers. In this paper, we propose a graphical Domain-Specific Modeling Language (DSML) to make it easier for non-technical users and domain specialists to implement an SC domain. The proposed language, SCLang, offers great expressiveness and flexibility. Six different methods of keystream generation are provided to obtain a random sequence. In addition, fifteen tests in the NIST suite are provided for random statistical analysis. The concepts of the SC domain and their relationships are presented in a meta-model. The evaluation of SCLang is based on qualitative analysis and is presented to demonstrate its effectiveness and efficiency.

Data management and storage have undergone a revolution with the introduction of cloud computing, which has made strong encryption methods necessary to guarantee data security. The use of the Triple Data Encryption Standard (3DES) method to improve data security in cloud computing settings is examined in this study. The approach consists of performance optimization strategies, key management protocols, and comprehensive encryption and decryption stages. Compared to ordinary DES, Triple DES offers a better degree of security by using three 56-bit keys and a mix of encryption and decryption phases. Secure random generation, key derivation functions, and secure storage and delivery procedures all deal with key management. Efficient key scheduling and parallel processing lead to performance optimization. Cryptographic libraries like OpenSSL and Bouncy Castle are used in cloud contexts, and cloud service platforms like AWS KMS and Azure Key Vault are utilized for secure key management. Triple DES is a strong option for protecting data in the cloud, as evidenced by performance and security tests that show the algorithm's computational cost, throughput, resistance to brute-force assaults, and vulnerability to cryptographic attacks.