Stream Cipher Research Articles

From Collatz Conjecture to chaos and hash function

The non-linear property of Chaos is a promising approach to information security, and many accomplishments have been made by combining Chaos with several sub-security domains, including chaos-based stream ciphers, block ciphers, image encryption, and hash functions. Most Chaos-based hash functions are insecure or inefficient due to their dependence on complex, attacked multi-dimensional maps or uncertain, weak one-dimensional maps like logistic and tent. The Collatz Conjecture is a mystery that has stumped mathematicians for decades and still has not been solved. This paper aims to introduce a novel approach to addressing current security challenges by utilizing our generalized Collatz process to create a chaos-based hash function. By leveraging the unpredictable behaviour of the Collatz sequence, the proposed hash function aims to enhance ergodicity and entropy properties, thereby making it well-suited for cryptographic applications. In the proposed method, the chaotic variables are governed by cryptographic keys, crucial in generating data sequences. These sequences are then utilized within the diffusion and confusion structures of the hashing function. The design of the chaos-hash model is carefully optimized to exhibit desirable characteristics such as randomness, collision resistance, uniformity, sensitivity to initial conditions, speed, and resistance against cryptanalysis.The primary goal of this research is to develop a robust and efficient chaos-based hash function that addresses the requirements of cryptographic systems. By incorporating the Collatz process and carefully considering key-controlled variables, the proposed model aims to offer enhanced security properties while meeting the necessary criteria for a reliable and effective hashing mechanism. The effectiveness and dependability of the proposed hash function are evaluated by comparing it with two well-known hash algorithms, namely SHA-3 and SHA-2, as well as several other Chaos-based hash algorithms. Through comprehensive evaluations conducted under various circumstances and with different datasets, the suggested hash function consistently outperforms the state-of-the-art alternatives. Experiments involving diverse input scenarios consistently demonstrate that the proposed hash function surpasses the performance of the current leading alternatives. Its superior performance is observed across various evaluation metrics, confirming its effectiveness in generating reliable and secure hash values. The results obtained from the comparative analysis highlight the superiority of the proposed hash function over existing alternatives, validating its potential as a robust solution for various cryptographic applications.

A General Correlation Evaluation Model on LFSR-Based Stream Ciphers

In this paper, a general model for evaluating the correlations of correlation attack distinguishers for an LFSR-based stream cipher is given by the Walsh spectrum theory of composite functions. We transform equivalently the linear approximations with <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">k</i> consecutive keystream words into that of a composite function consisting of several simple functions, which enables cryptanalysts to derive linear approximations of any LFSR-based stream cipher by this model and to search for linear trails with high absolute correlations. This model suits any LFSR-based stream cipher, does not need the implicit independence assumption widely used in previous cryptanalysis, and can theoretically ensure that the correlation obtained is the accurate correlation of a correlation attack distinguisher. In addition, we prove that it is enough to consider the distinguishers where the masks of all LFSR elements are zero except for those of a maximal linearly independent system of LFSR elements involved in the update function and output function. As applications, the approximation processes for the correlation attack distinguishers of SNOW-V, SNOW2.0, ZUC, and Grain-128 are exhibited respectively by this method. Moreover, by the proposed method we can perform a full coverage search for binary linear approximations of them. For SNOW-V, we prove that the approximation given by our model is equivalent to that by Shi et al. at EUROCRYPT 2022, and is simpler and more intuitive. For SNOW2.0, we find more linear approximations with the best correlation. For ZUC, for the first time we get the accurate correlations of a series of linear approximations including the known results, and give the supremum of the absolute correlations for a larger set of linear approximations. For Grain-128, utilizing our method, we rediscover the best known correlation as well, which provides more support for the validity of our general model. Our work can give some evidence for the provable security of LFSR-based stream ciphers against correlation attack to some extent, and may provide the key clues in the analysis of complex stream ciphers.

A unified construction of weightwise perfectly balanced Boolean functions

At Eurocrypt 2016, Méaux et al. presented FLIP, a new family of stream ciphers that aimed to enhance the efficiency of homomorphic encryption frameworks. Motivated by FLIP, recent research has focused on the study of Boolean functions with good cryptographic properties when restricted to subsets of the space F2n. If an n-variable Boolean function has the property of balancedness when restricted to each set of vectors with fixed Hamming weight between 1 and n−1, it is a weightwise perfectly balanced (WPB) Boolean function. In the literature, a few algebraic constructions of WPB functions are known, in which there are some constructions that use iterative method based on functions with low degrees of 1, 2, or 4. In this paper, we generalize the iterative method and contribute a unified construction of WPB functions based on functions with algebraic degrees that can be any power of 2. For any given positive integer d not larger than m, we first provide a class of 2m-variable Boolean functions with a degree of 2d−1. Utilizing these functions, we then present a construction of 2m-variable WPB functions gm;d. In particular, gm;d includes four former classes of WPB functions as special cases when d=1,2,3,m. When d takes other integer values, gm;d has never appeared before. In addition, we prove the algebraic degree of the constructed WPB functions and compare the weightwise nonlinearity of WPB functions known so far in 8 and 16 variables.

Multi-Layer QCA Shift Registers and Wiring Structure for LFSR in Stream Cipher with Low Energy Dissipation in Quantum Nanotechnology

Pseudorandom numbers (PRN) are used in various cryptographic applications, such as cryptographic protocols and stream ciphers. The most efficient hardware method used to generate PRNs is to use a Linear Feedback Shift Register (LFSR) structure, which is generally composed of a Shift Register (SR) and an XOR gate. The most important factors in designing the entire LFSR structure are design cost and energy efficiency, which are highly dependent on the SR structure. In the proposed study, the structural characteristics and problems of existing various types of SRs are presented, and new multi-layered serial-in-serial-out (SISO) and parallel-in-parallel-out (PIPO) SRs are proposed. In addition, we compare and analyze the area-time complexity, design cost, and energy dissipation through simulation using QCADesigner and QCADesigner-E. As a result, the proposed SISO and PIPO showed a performance improvement of more than 27% compared to the existing structure, which showed the best performance, and showed energy dissipation reduction rates of about 65% and 59%, respectively. In particular, we proposed multi-layer wiring that can reduce energy dissipation and verified through simulation that it can save up to 24.8%.

On security of GIS systems with N-tier architecture and family of graph based ciphers

Discovery of q-regular tree description in terms of an infinite system of quadratic equations over finite field Fq had an impact on Computer Science, theory of graph based cryptographic algorithms in particular. It stimulates the development of new graph based stream ciphers. It turns out that such encryption instruments can be efficiently used in GIS protection systems which use N-Tier Architecture. We observe known encryption algorithms based on the approximations of regular tree, their modifications defined over arithmetical rings and implementations of these ciphers. Additionally new more secure graph based ciphers suitable for GIS protection will be presented.Algorithms are constructed using vertices of bipartite regular graphs D(n,K) defined by a finite commutative ring K with a unit and a non-trivial multiplicative group K*. The partition of such graphs are n-dimensional affine spaces over the ring K. A walk of even length determines the transformation of the transition from the initial to the last vertex from one of the partitions of the graph. Therefore, the affine space Kn can be considered as a space of plaintexts, and walking on the graph is a password that defines the encryption transformation.With certain restrictions on the password the effect when different passwords with K*)2s, s &lt;[(n+5)/2]/2 correspond to different ciphertexts of the selected plaintext with Kn can be achieved.In 2005, such an algorithm in the case of the finite field F127 was implemented for the GIS protection. Since then, the properties of encryption algorithms using D(n, K) graphs (execution speed, mixing properties, degree and density of the polynomial encryption transform) have been thoroughly investigated.The complexity of linearization attacks was evaluated and modifications of these algorithms with the resistance to linearization attacks were found. It turned out that together with D(n, K) graphs, other algebraic graphs with similar properties, such as A(n, K) graphs, can be effectively used.The article considers several solutions to the problem of protecting the geological information system from possible cyberattacks using stream ciphers based on graphs. They have significant advantages compared to the implemented earlier systems.

Integration of Self-Adaptive Physical-Layer Key Distribution and Encryption in Optical Coherent Communication

We propose and experimentally demonstrate a compatible physical-layer secure optical communication (PLSOC) system that integrates self-adaptive physical-layer key distribution (PLKD) and encryption (PLE) in optical coherent communication. Based on bit error rate difference of QAM signals mapped by asymmetric basis state Y-00 protocol, the secret key can be secretly exchanged over public fiber links without the pre-shared keys. Moreover, we perform a parameter self-adaptive strategy for practical and dynamic PLKD. The security of the key is evaluated in the case of a fiber-tapping attack. A secure hash algorithm, SHA3-512, is used to perform privacy amplification to obtain the virtually secure key. An error-free PLKD rate reaches 39.3 Kbits/s over 300km ultra-low loss fiber. We experimentally enable the integration of the proposed PLKD scheme and quantum noise stream cipher (QNSC) with a single wavelength, same system. Q factor penalty of the integration system compared to the QNSC system is 3.7dB (optical back-to-back) and 4.8dB (300km) respectively. By exploiting a common hardware platform, with the same wavelength, the proposed PLSOC system addresses the problem that PLKD and PLE are separately performed through independent optical fiber links or wavelengths. Since only digital signal processing is used, the scheme does not require extra hardware.

Deep Learning based Analysis of Stream Ciphers A5/1 and RC4

Deep Learning based Analysis of Stream Ciphers A5/1 and RC4

Matrix Encryption Walks for Lightweight Cryptography

In this paper, we propose a new symmetric stream cipher encryption algorithm based on Graph Walks and 2-dimensional matrices, called Matrix Encryption Walks (MEW). We offer example Key Matrices and show the efficiency of the proposed method, which operates in linear complexity with an extremely large key space and low-resource requirements. We also provide the Proof of Concept code for the encryption algorithm and a detailed analysis of the security of our proposed MEW. The MEW algorithm is designed for low-resource environments such as IoT or smart devices and is therefore intended to be simple in operation. The encryption, decryption, and key generation time, along with the bytes required to store the key, are all discussed, and similar proposed algorithms are examined and compared. We further discuss the avalanche effect, key space, frequency analysis, Shannon entropy, and chosen/known plaintext-ciphertext attacks, and how MEW remains robust against these attacks. We have also discussed the potential for future research into algorithms such as MEW, which make use of alternative structures and graphic methods for improving encryption models.

Revisiting the Software-Efficient Stream Ciphers RCR-64 and RCR-32

Abstract The synchronous stream ciphers RCR-64 and RCR-32 designed by Sekar, Paul and Preneel are strengthened variants of the ciphers TPy and TPypy (designed by Biham and Seberry), respectively. The RCR ciphers have remained unbroken since they were published in 2007. In this paper, we present arguments that not only support the designers’ security claims but suggest, in general, that the ciphers are secure against several classes of cryptanalytic attacks. We find that the ciphers are best used with 256-bit keys and 384-bit IVs. We also suggest ways to protect software implementations of the RCR ciphers against (cache-)timing and processor flag attacks. Our performance evaluation suggests that the protected implementation of the RCR-64 encrypts long messages at speeds comparable to some of the fastest stream ciphers available today. Consequently, we find that the RCR ciphers may be well suited for PC-based applications in general and streaming audio / video applications in particular. This is the first paper to present a detailed study on the security and performance of the RCR ciphers.

The welch-gong stream cipher - evolutionary path

This survey presents the rich history of the Welch-Gong (WG) Stream cipher family. It has been a long journey that lead the WG stream ciphers to become practical. The evolutionary path is a combination of mathematical endeavour and engineering striving to transfer pure mathematical functions to practical encryption algorithms for various applications. This path began as the pioneering work on WG transformation sequences with 2-level autocorrelation, leading to important breakthroughs in the early 2000’s, such as the submission of the first WG stream cipher to the eSTREAM competition in 2005 and the subsequent introduction of the WG stream cipher family WG(m, l), followed by extensive work on particular instances proposed for various (mostly lightweight) applications. A recent construction using a WG permutation is the authenticated encryption WAGE, submitted to the NIST LWC competition in 2019. The story of the WG stream cipher is by far not finished. The future opens numerous possibilities for WG stream ciphers and WAGE, with applications in both lightweight environments and in high-performance computing. We conclude the survey with new ideas and open problems.

Fast Correlation Attacks on K2 Stream Cipher

K2 is an LFSR-based dynamic feedback stream cipher and has been standardized by ISO/IEC 18033-4. The fast correlation attack (FCA) is a well-known cryptanalysis tool for LFSR-based stream ciphers. In this paper, we propose a guess-and-determine FCA on a dynamic feedback stream ciphers model. Moreover, we give a fast calculation method to calculate the correlation of the function <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">F(x, y, z)</i> = <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</i> ⊞ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><i>n</i></sub> <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">S(y)</i> ⊟ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><i>n</i></sub> <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">z</i> by directly characterizing subtraction modulo 2 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><i>n</i></sup> . Then we propose a kind of mask structure of the linear approximations of the function <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">F(x, y, z)</i> with high correlations. The structural characteristics of the kind of masks reduce both the time complexity of the fast calculation and the memory complexity of connection matrices, which enables us to efficiently search for linear approximations with high correlations. Based on the structural characteristics and the analysis of the number of active S-boxes of the linear approximations of K2, we present an effective search strategy, where the number of active S-boxes is 4. The best absolute correlation we found is 2 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">–24.21</sup> . Finally, we study the resistance of K2 against the FCA. For any of the four variants of K2, we give the best key recovery attack so far. The time/data/memory complexity is <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">O</i> (2 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">190.06</sup> )/ <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">O</i> (2 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">189.80</sup> )/ <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">O</i> (2 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">188.80</sup> ), respectively. The results indicate that the four variants of K2 cannot guarantee the claimed 192-bit and 256-bit security if we ignore the design constraint that the maximum keystream length for a single pair of key and IV is limited to 2 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">64</sup> . For the full version of K2, we present the first FCA, which is also the best attack result yet. And the time/data/memory complexity is <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">O</i> (2 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">313.57</sup> )/ <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">O</i> (2 <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">149.02</i> )/ <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">O</i> (2 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">148.02</sup> ), respectively. The large security redundancy indicates that the dynamic feedback structure provides higher security.

Securing Embedded System from Code Reuse Attacks: A Lightweight Scheme with Hardware Assistance.

The growing prevalence of embedded systems in various applications has raised concerns about their vulnerability to malicious code reuse attacks. Current software-based and hardware-assisted security techniques struggle to detect or block these attacks with minor performance and implementation overhead. To address this issue, this paper presents a lightweight hardware-assisted scheme to enhance the security of embedded systems against code reuse attacks. We develop an on-chip lightweight hardware shadow stack to validate target addresses at runtime for backward-edge control flow integrity, which backs up valid return addresses during function calls and automatically verifies actual return addresses during the return phase. Additionally, we propose a lightweight stream cipher circuit that encrypts and decrypts critical stack data related to control flow manipulation, preventing attackers from analyzing or tampering with them. When designing and implementing the security mechanism for embedded systems, we fully consider the constraints of limited system resources and performance, optimizing both the architecture design and implementation of the proposed hardware. Finally, we integrate both the proposed lightweight hardware shadow stack and the runtime data encryption hardware into the OR1200 processor. We have verified the system security function on the Terasic DE1-SoC FPGA platform and evaluated the system performance as well as implementation overhead. The results show that the proposed lightweight hardware-assisted scheme can provide a dedicated defense capability against code reuse attacks for embedded systems, with an average system performance overhead of 0.39% and an area footprint of 0.316 mm2.

REVERSIBLE WATERMARKING ALGORITHM WITH CHAOS AND ZUC ENCRYPTION BASED ON DEEP LEARNING IN HEALTHCARE

In view of the shortcomings of the existing reversible watermarking algorithms for encrypted images, such as low embedding rate and incomplete separation, and at the same time ensuring the embedding rate and the quality of the watermarked image, this paper proposes a reversible watermarking algorithm for encrypted images with high embedding rate and separable effect. This paper proposes a reversible watermarking algorithm for encrypted images with high embedding rate and separable effect. First, the plaintext image is encrypted by using the encryption series generated by chaotic system and Zu Chongzhi’s encryption algorithm; Second, analyze the PSNR value of the image under different interpolation conditions, generate the corresponding expected interpolation, and embed the watermark information into the image based on the expected interpolation; Finally, the original image can be recovered by using the encryption key, and the watermark information can be obtained by using the embedded key. The security and embedding ability of the algorithm are analyzed through simulation experiments. The results show that the introduction of ZUC stream cipher can expand the key space of the algorithm, have high security and achieve the separable effect. The embedding of watermark information has little impact on the ciphertext image, and the embedding rate is also higher than the contrast algorithm under the condition of ensuring the visual effect of the image.

PRISMA Archetype-Based Systematic Literature Review of Security Algorithms in the Cloud

Industries have embraced cloud computing for their daily operations due to the volume of data they create. As data generation and consumption have increased, the challenges and opportunities have also increased. Researchers have proposed various cryptographic schemes to secure data on the cloud. Regardless of the multiple cryptographic schemes proposed, security remains an obstacle to cloud computing’s widespread adoption. Also, these cryptographic schemes’ run times are proportional to data sizes, motivating excessive CPU engagement during execution of huge data, which has consequences for the need for high bandwidth to transfer data to the cloud. This systematic review tries to uncover the most often used cryptographic schemes and their run time trends to attain confidentiality and privacy of cloud data. The study considered published articles from well-known databases such as Taylor &amp; Francis, Scopus, Research Gate, Web of Science, IEEE Xplore, Science Direct, Hindawi, Google Scholar, Sage, Emerald, Wiley Online Library, and ACM from 2016 to 2022. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were used to select 73 published works for this study using keyword searching. Data security and cloud security were the security challenges that received the greatest attention in the study with encryption techniques as the most common solution. From the study, 90% of the schemes used to secure data on the cloud produced linear run times. The investigation discovered that nonlinear symmetric stream cipher methods were infrequently employed to protect the secrecy and privacy of cloud data.

Design and Analysis of a new Stream Cipher based on Ring FCSR Automaton

Design and Analysis of a new Stream Cipher based on Ring FCSR Automaton

Provable security against generic attacks on stream ciphers

Abstract Recent lightweight hardware-based stream cipher designs keep an external non-volatile internal state that is not part of the cipher’s hardware module. The purpose of these so-called small-state ciphers is to keep the size of the hardware and the power consumption low. We propose a random oracle model for stream ciphers. This will allow us to analyse the recent small-state stream cipher designs’ resistance against generic attacks and, in particular, time-memory-data tradeoff attacks. We analyse the conventional construction underlying stream ciphers like Grain and Trivium, constructions continuously using the external non-volatile secret key during keystream generation like Sprout, Plantlet, Fruit, and Atom, constructions continuously using the external non-volatile IV, and constructions using a combination of the IV and the key like DRACO. We show the tightness of all bounds by first presenting the time-memory-data tradeoff attacks on the respective constructions, establishing the upper bound on security, and then presenting the proof of security to establish the lower bound on security. In this work, we extend the theoretical work done by Hamann et al. who introduced the DRACO stream cipher at FSE 2023. We use the same random oracle model as the aforementioned work and apply it to the earlier work by Hamann et al. presented at SAC 2019, which showed security for two of the four constructions we consider in this work. Our model is equivalent but allows for a much simpler proof of security. Furthermore, we provide a proof of security for stream ciphers continuously using the secret key during keystream generation, giving upper and lower bounds for all four generic stream cipher constructions proposed so far.

Ukrainian National Encryption Standards for FPGA Based Embedded Systems

The paper presents the hardware implementation based on FPGA of the main cryptographic transformations of the symmetric transformation algorithm of DSTU 7624:2014 and the stream cipher of DSTU 8845:2019, which are the national encryption standards of Ukraine. In the case of DSTU 7624: 2014 developed and implemented a hardware implementation for multiplication of two polynomials modulo x8+x4+x3+x2+1 in the form of a combinational circuit that allows to execute the MixColumn transformation by one cycle. SubBytes transformation is implemented based on asynchronous read-only memory. For stream cipher, DSTU 8845:2019 the nonlinear function T are implemented as subtitution byte operation in the form of precalculated cells of ROM memory. The multiplication function by α and α-1 in Galois field arithmetic GF (2 64) is realized based on ROM and combinational logic. The control of the modes of operation of the shift register with linear feedback is performed based on a FSM. Both hardware implementations of encryption standards have been verified by the authors according to the specified data in the standard, and their HDL code can be provided by the authors for further research to interested parties.

Image Encryption Using New Non-Linear Stream Cipher Cryptosystem

In this paper, we designed a new efficient stream cipher cryptosystem that depends on a chaotic map to encrypt (decrypt) different types of digital images. The designed encryption system passed all basic efficiency criteria (like Randomness, MSE, PSNR, Histogram Analysis, and Key Space) that were applied to the key extracted from the random generator as well as to the digital images after completing the encryption process.

Characterizing a Time–Memory Tradeoff Against PudgyTurtle

PudgyTurtle is not a cipher, but rather an alternative way to utilize the keystream in binary-additive stream-cipher cryptosystems. Instead of modulo-2 adding the keystream to the plaintext, PudgyTurtle uses the keystream to encode 4-bit groups of plaintext, and then to encipher each codeword. One goal of PudgyTurtle is to make time–memory tradeoff attacks more difficult. Here, we investigate one such attack (a modification of the well-known Babbage–Golić method), and show that its time-complexity is harder on average than an analogous tradeoff attack against a standard binary-additive stream cipher; may approach that of a ’brute-force’ attack; can be reduced by certain parameter choices; and can be formulated in terms of a probability distribution which is amenable to simulation.

Design Space Exploration of Galois and Fibonacci Configuration Based on Espresso Stream Cipher

Fibonacci and Galois are two different kinds of configurations in stream ciphers. Although many transformations between two configurations have been proposed, there is no sufficient analysis of their FPGA performance. Espresso stream cipher provides an ideal sample to explore such a problem. The 128-bit secret key Espresso is designed in Galois configuration, and there is a Fibonacci-configured Espresso variant proved with the equivalent security level. To fully leverage the efficiency of two configurations, we explore the hardware optimization approaches toward area and throughput, respectively. In short, the FPGA-implemented Fibonacci cipher is more suitable for extremely resource-constrained or high-throughput applications, while the Galois cipher compromises both area and speed. To the best of our knowledge, this is the first work to systematically compare the FPGA performance of cipher configurations under relatively fair cryptographic security. We hope this work can serve as a reference for the cryptography hardware architecture research community.