Security Of Cipher Research Articles

Algebraic Persistent Fault Analysis of SKINNY_64 Based on S_Box Decomposition

Algebraic persistent fault analysis (APFA), which combines algebraic analysis with persistent fault attacks, brings new challenges to the security of lightweight block ciphers and has received widespread attention since its introduction. Threshold Implementation (TI) is one of the most widely used countermeasures for side channel attacks. Inspired by this method, the SKINNY block cipher adopts the S_box decomposition to reduce the number of variables in the set of algebraic equations and the number of Conjunctive Normal Form (CNF) equations in this paper, thus speeding up the algebraic persistent fault analysis and reducing the number of fault ciphertexts. In our study, we firstly establish algebraic equations for full-round faulty encryption, and then analyze the relationship between the number of fault ciphertexts required and the solving time in different scenarios (decomposed S_boxes and original S_box). By comparing the two sets of experimental results, the success rate and the efficiency of the attack are greatly improved by using S_box decomposition. In this paper, We can recover the master key in a minimum of 2000s using 11 pairs of plaintext and fault ciphertext, while the key recovery cannot be done in effective time using the original S_box expression equations. At the same time, we apply S_box decomposition to another kind of algebraic persistent fault analysis, and the experimental results show that using S_box decomposition can effectively reduce the solving time and solving success rate under the same conditions.

Effective Design of Secure Cipher Application Based on Digital Alteration Technical

In today’s era, communication and sharing of information is increasing rapidly. It is important to mention that Cryptography has been used for secure communication since it is regarded an important tool to protect the information in the modern world in computer systems. Many techniques can be used to implement the encryption like substitution and permutation or sometimes by some mathematical readability. The cipher text can be generated according to the human comprehension and readability after applying any of the aforementioned techniques. In this research, have studied and analyzed the current limitations and challenges of cipher and algorithms context from the perspective of security design. Then, we have identified the design dimensions and components of a secure cipher application based on digital alteration technical. Then, a secure cipher application based on digital change technical was constructed and developed. At last, we tested and evaluated the user interaction in cipher application prototype based on suggested technical. Through experience, it was confirmed that the digital alteration technical is useful and easy for users who work on text encryption.

Encryption Modes Identification of Block Ciphers based on Machine Learning

Encryption modes affect the security of block ciphers. This paper proposes a new approach for identifying encryption modes based on machine learning and feature engineering. In the conditions of random keys and initialization vectors, five encryption modes are used for identification. Each mode is encrypted by several block ciphers. By comparing with previous work, we have overcome the shortcomings and improved the accuracy of identification by about 30% to 40%. The experiments improve the existing results and can effectively help cryptanalysts recover the keys.

High-throughput block cipher implementations with SIMD

The development of new technologies has put forward higher requirements for the performance and security of block ciphers. To meet the needs of these situations, Bitslicing is one of the block cipher implementation techniques which can provide high efficiency and resistance to cache-timing attacks. The S-box is usually the most time-consuming component for Bitsliced implementations. In this paper, we present techniques to optimize the S-box implementation and derive the most compact representations available for Bitslicing. Then we show that the efficiency of linear layers can be further improved by introducing a state-of-the-art technique. As a result, our implementations have significant advantages over previous implementations. The throughputs of our AES and SM4 implementations achieve 27068Mbps and 30026Mbps on i5-11335G7, both exceeding the throughput of AES-NI on the same platform.

DAC/ADC-free 4 × 12.9 Gbit/s 65,536-level quantum noise stream cipher secure optical WDM transmission based on delta-sigma modulation.

We propose and experimentally study a novel, to the best of our knowledge, quantum noise stream cipher (QNSC) secure transmission scheme based on the delta-sigma modulation (DSM) technique. The cooperation of the QNSC and DSM mechanisms makes it possible to transmit an ultrahigh-order encrypted signal in the non-return-to-zero (NRZ) on-off keying (OOK) format. The delivery of the NRZ OOK waveform over the fiber link allows us to send and receive signals using digital ports, instead of high-speed and high-resolution digital-to-analog converters (DACs) and analog-to-digital converters (ADCs)in conventional QNSC systems. Meanwhile, clock synchronization can be achieved by using a simple clock data recovery algorithm. The extra clock signal transmission link in conventional QNSC systems is no longer needed. The proposed scheme is also compatible with wavelength division multiplexing (WDM) systems. In this work, 4 × 12.9 Gbit/s plaintext is encrypted to a 65,536-level QNSC signal and then transmitted over a 10-km standard single-mode fiber. The transmitter and receiver are established by commercial 100G QSFP28 optical modules with clock data recovery. This proposed scheme can be easily deployed in commercial systems due to its minimalist implementation architecture and relatively low hardware cost.

Short Non-Malleable Codes from Related-Key Secure Block Ciphers, Revisited

We construct non-malleable codes in the split-state model with codeword length m + 3λ or m + 5λ, where m is the message size and λ is the security parameter, depending on how conservative one is. Our scheme is very simple and involves a single call to a block cipher meeting a new security notion which we dub entropic fixed-related-key security, which essentially means that the block cipher behaves like a pseudorandom permutation when queried upon inputs sampled from a distribution with sufficient min-entropy, even under related-key attacks with respect to an arbitrary but fixed key relation. Importantly, indistinguishability only holds with respect to the original secret key (and not with respect to the tampered secret key).In a previous work, Fehr, Karpman, and Mennink (ToSC 2018) used a related assumption (where the block cipher inputs can be chosen by the adversary, and where indistinguishability holds even with respect to the tampered key) to construct a nonmalleable code in the split-state model with codeword length m + 2λ. Unfortunately, no block cipher (even an ideal one) satisfies their assumption when the tampering function is allowed to be cipher-dependent. In contrast, we are able to show that entropic fixed-related-key security holds in the ideal cipher model with respect to a large class of cipher-dependent tampering attacks (including those which break the assumption of Fehr, Karpman, and Mennink).

Characteristic automated search of cryptographic algorithms for distinguishing attacks (CASCADA)

Automated search methods based on Satisfiability Modulo Theory (SMT) problems are being widely used to evaluate the security of block ciphers against distinguishing attacks. While these methods provide a systematic and generic methodology, most of their software implementations are limited to a small set of ciphers and attacks, and extending these implementations requires significant effort and expertise. In this work, the authors present cryptographic algorithms for distinguishing attacks (CASCADA), an open-source Python library to evaluate the security of cryptographic primitives, specially block ciphers, against distinguishing attacks with bit-vector SMT solvers. The tool CASCADA implements the bit-vector property framework herein proposed and several SMT-based automated search methods to evaluate the security of ciphers against differential, related-key differential, rotational-XOR, impossible-differential, impossible-rotational-XOR, related-key impossible-differential, linear and zero-correlation cryptanalysis. The library CASCADA is the result of a huge engineering effort, and it provides many functionalities, a modular design, an extensive documentation and a complete suite of tests.

SPEEDY Quantum Circuit for Grover’s Algorithm

In this paper, we propose a quantum circuit for the SPEEDY block cipher for the first time and estimate its security strength based on the post-quantum security strength presented by NIST. The strength of post-quantum security for symmetric key cryptography is estimated at the cost of the Grover key retrieval algorithm. Grover’s algorithm in quantum computers reduces the n-bit security of block ciphers to n2 bits. The implementation of a quantum circuit is required to estimate the Grover’s algorithm cost for the target cipher. We estimate the quantum resource required for Grover’s algorithm by implementing a quantum circuit for SPEEDY in an optimized way and show that SPEEDY provides either 128-bit security (i.e., NIST security level 1) or 192-bit security (i.e., NIST security level 3) depending on the number of rounds. Based on our estimated cost, increasing the number of rounds is insufficient to satisfy the security against quantum attacks on quantum computers.

A Visually Secure Image Encryption Based on the Fractional Lorenz System and Compressive Sensing

Recently, generating visually secure cipher images by compressive sensing (CS) techniques has drawn much attention among researchers. However, most of these algorithms generate cipher images based on direct bit substitution and the underlying relationship between the hidden and modified data is not considered, which reduces the visual security of cipher images. In addition, performing CS on plain images directly is inefficient, and CS decryption quality is not high enough. Thus, we design a novel cryptosystem by introducing vector quantization (VQ) into CS-based encryption based on a 3D fractional Lorenz chaotic system. In our work, CS compresses only the sparser error matrix generated from the plain and VQ images in the secret generation phase, which improves CS compression performance and the quality of decrypted images. In addition, a smooth function is used in the embedding phase to find the underlying relationship and determine relatively suitable modifiable values for the carrier image. All the secret streams are produced by updating the initial values and control parameters from the fractional chaotic system, and then utilized in CS, diffusion, and embedding. Simulation results demonstrate the effectiveness of the proposed method.

A New Hyperchaotic System Generated by an External Periodic Excitation and its Image Encryption Application

By using a controller of uniformly bounded sine function, the problem of chaos anti-control for continuous linear systems is studied, and the dynamic characteristics of the controlled system are analyzed via the Lyapunov exponent spectrum and bifurcation diagram. The controlled system can be at a state of periodic motion, chaos or hyperchaos with multiple positive Lyapunov exponents when the parameters of controller belong to different intervals. Based on the hyperchaotic system, a new scheme of chaotic image encryption is proposed and it is given in the following aspects: (1) five chaotic sequences are generated from the hyperchaotic system, and the preprocessed pseudo-random sequences are used in the scrambling of the pixel positions; (2) the pixel values of image are encrypted by the combination of multiple pseudo-random sequences; (3) though the double chaotic encryption, the security of the chaotic stream cipher is analyzed by means of key sensitivity analysis, histogram analysis and information entropy analysis, etc. Finally, the experimental results show the scheme is effective and feasible in image encryption, and it can resist some attacks, such as the differential attacks, chosen-plain-text attacks, and clipping attacks.

Rating of Modern Color Image Cryptography: A Next-Generation Computing Perspective

Issues such as inefficient encryption architectures, nonstandard formats of image datasets, weak randomness of chaos-based Pseudorandom Number Generators (PRNGs), omitted S-boxes, and unconvincing security metrics leading to increased computational time and inadequate security level of chaos and Deoxyribonucleic Acid- (DNA-) based image encryption schemes need careful examination towards the development of more stable encryption schemes in terms of efficiency and reasonable security. A new taxonomy of image encryption based on chaotic systems, hyperchaotic systems, and DNA is propounded to assess the impact of these issues on the performance and security metrics. The primary emphasis of this research is to study various recent encryption architectures centered on a variety of confusion and diffusion methods. It is aimed at assessing the performance and security of various ciphers using a cipher rating criterion that categorizes ciphers into different classes. The parameters that are included in the rating criteria are information entropy, chi-squared goodness of fit test for histogram uniformity analysis, encryption efficiency, key space, differential attacks (Number of Pixels Change Rate and Universal Average Changing Intensity), key sensitivity analysis, encryption time, randomness tests such as NIST-R (a statistical suite for validating the randomness designed by the National Institute of Standards and Technology), correlation coefficient analysis, contrast analysis, energy analysis, homogeneity analysis, Mean Absolute Error, peak signal-to-noise ratio, and robustness to noise and occlusion attacks.

On Grain-Like Small State Stream Ciphers Against Fast Correlation Attacks: Cryptanalysis of Plantlet, Fruit-v2 and Fruit-80

Abstract The fast correlation attack (FCA) is one of the most important cryptanalytic techniques against LFSR-based stream ciphers. In CRYPTO 2018, Todo et al. found a new property for the FCA and proposed a novel algorithm which was successfully applied to the Grain family of stream ciphers. Nevertheless, these techniques cannot be directly applied to Grain-like small state stream ciphers with keyed update, such as Plantlet, Fruit-v2 and Fruit80. In this paper, we study the security of Grain-like small state stream ciphers by the FCA. We first observe that the number of required parity-check equations can be reduced when there are multiple different parity-check equations. With exploiting the Skellam distribution, we introduce a sufficient condition to identify the correct LFSR initial state and derive a new relationship between the number and bias of the required parity-check equations. Then, a modified algorithm is presented based on this new relationship, which can recover the LFSR initial state no matter what the round key bits are. Under the condition that the LFSR initial state is known, an algorithm is given against the degraded system and to recover the NFSR state at some time instant, along with the round key bits. As cases study, we apply our cryptanalytic techniques to Plantlet, Fruit-v2 and Fruit-80. As a result, for Plantlet, our attack takes $ 2^{73.75} $ time complexity and $ 2^{73.06} $ keystream bits to recover the full 80-bit key. Regarding Fruit-v2, $ 2^{55.34} $ time complexity and $ 2^{55.62} $ keystream bits are needed to determine the secret key. As for Fruit-80, $2^{64.47}$ time complexity and $2^{62.82}$ keystream bits are required to recover the secret key. More flexible attacks can be obtained with lower data complexity at the cost of increasing the attack time. Especially, for Fruit-v2, a key recovery attack can be launched with data complexity of $2^{42.38}$ and time complexity of $2^{73.31}$. Moreover, we have implemented our attack methods on a toy version of Fruit-v2. The attack matches the expected complexities predicted by our theoretical analysis quite well, which proves the validity of our cryptanalytic techniques.

New Meet-in-the-Middle Attacks on FOX Block Cipher

Abstract FOX block cipher was designed with a Lai–Massey scheme, in which the round function uses the Substitution-Permutation-Substitution structure. A meet-in-the-middle (MITM) attack is one of the most important issues for the security of the block cipher, which consists of a precomputation phase for constructing a distinguisher and an online phase for key recovery. This paper studies the MITM attacks against FOX. The first MITM distinguishers of 5-round FOX64, 7-round FOX64-256 and 5-round FOX128 are presented when using the differential enumeration technique with truncated differential characteristics. Then, based on these distinguishers, the attacks for key recovery on 7-round FOX64, 11-round FOX64-256 and 7-round FOX128 are presented with the state-test and state-search techniques. It is shown that the attack on 11-round FOX64-256 is proposed for the first time; attacks on 7-round FOX64 and 7-round FOX128 can be improved with lower time and memory complexities compared with the currently known attacks.

Quantum security of AES-128 under HHL algorithm

There have been a lot of researches about algebric analysis of AES. In this paper, we turned to quantum algorithm to analyze security of AES-128 against the modified HHL algorithm, which is a quantum algorithm used to get classical solutions of multivariate equation system. We constructed two types of equation systems of AES, and solved them with several variants of HHL algorithms respectively. The resulting complexities involved the condition number are given. We analyzed the reasons for the different complexity of the two equation systems and their solution methods, and pointed out that the combination of the boolean equation system and (the improved) BoolSol is more threatening to AES. With a lower bound on the condition number presented by Ding et al., we show that, for AES-128, HHL algorithm is difficult to achieve better attack effect than Grover algorithm. Our results have some enlightening significance for analyzing the post-quantum security of AES-like block ciphers.

Automated enumeration of block cipher differentials: An optimized branch-and-bound GPU framework

Block ciphers are prevalent in various security protocols used daily such as TLS, OpenPGP, and SSH. Their primary purpose is the protection of user data, both in transit and at rest. One of the de facto methods to evaluate block cipher security is differential cryptanalysis. Differential cryptanalysis observes the propagation of input patterns (input differences) through the cipher to produce output patterns (output differences). This probabilistic propagation is known as a differential; the identification of which is a measure of a block cipher’s security margins. This paper introduces an optimized GPU-based branch-and-bound framework for differential search. We optimize search efficiency by parallelizing all branch-and-bound operations, completing the entire search on the GPU without communicating with the CPU. The meet-in-the-middle (MITM) approach is also adopted for further performance gains. We analyze the financial and computational costs of the proposed framework using Google Cloud VM to showcase its practicality. When optimized for performance, we can attain up to 90x speedup while saving up to 47% of the running cost as compared to a single CPU core. When optimized for cost, the proposed framework can save up to 83% of financial costs while retaining a speedup of up to 40x. As a proof of concept, the proposed framework was then applied on 128-bit TRIFLE-BC, 64-bit PRESENT, and 64-bit GIFT. Notably, we identified the best differentials for PRESENT (16 rounds) and 64-bit GIFT (13 rounds) to date, with estimated probabilities of 2−61.7964 and 2−60.66 respectively. Although the differential results for TRIFLE-BC were incremental, the proposed framework was able to construct differentials for 43 rounds that consisted of approximately 5.8x more individual trails than previous work, making it one of the most efficient approaches for larger block ciphers.

A Monte Carlo Based COVID-19 Detection Framework for Smart Healthcare

COVID-19 is a novel coronavirus disease that has been declared as a global pandemic in 2019. It affects the whole world through person-to-person communication. This virus spreads by the droplets of coughs and sneezing, which are quickly falling over the surface. Therefore, anyone can get easily affected by breathing in the vicinity of the COVID-19 patient. Currently, vaccine for the disease is under clinical investigation in different pharmaceutical companies. Until now, multiple medical companies have delivered health monitoring kits. However, a wireless body area network (WBAN) is a healthcare system that consists of nano sensors used to detect the real-time health condition of the patient. The proposed approach delineates is to fill a gap between recent technology trends and healthcare structure. If COVID-19 affected patient is monitored through WBAN sensors and network, a physician or a doctor can guide the patient at the right time with the correct possible decision. This scenario helps the community to maintain social distancing and avoids an unpleasant environment for hospitalized patients Herein, a Monte Carlo algorithm guided protocol is developed to probe a secured cipher output. Security cipher helps to avoid wireless network issues like packet loss, network attacks, network interference, and routing problems. Monte Carlo based covid-19 detection technique gives 90% better results in terms of time complexity, performance, and efficiency. Results indicate that Monte Carlo based covid-19 detection technique with edge computing idea is robust in terms of time complexity, performance, and efficiency and thus, is advocated as a significant application for lessening hospital expenses.

Evaluating the performance of post-quantum secure algorithms in the TLS protocol

Aim: The imminent advent of large-scale quantum computers within the next years is expected to highly affect the security of several cryptosystems that are now considered secure; this mainly holds for classical, long-established, public key cryptographic algorithms such as RSA and elliptic curve cryptography. Apparently, any security protocol that relies on such ciphers, including the transport layer security (TLS) protocol which constitutes a somewhat de facto standard for the security on the web, will not be considered secure in the post-quantum era. To alleviate the security risks stemming from quantum computing, several proposals have been submitted to the relevant procedure initiated by NIST towards evaluating and standardizing one or more quantum-resistant public-key cryptographic algorithms. This paper focuses on embedding post-quantum secure cryptographic algorithms into the TLS protocol to analyze its performance. More precisely, the paper aims to analyze whether this transition to post-quantum secure algorithms will have a significant impact on the user experience due to the possible increase of client--server communication times. Methods: Having as the starting point several important works in the field, several experiments were carried out, using combinations of cloud and local virtual machines per case and considering all the post-quantum cryptographic algorithm finalists for key exchange from the third round of the ongoing NIST process, for various cryptographic as well as network parameters. Results: Our results exhibit that, for key exchange in TLS, the best performance among the post-quantum secure ciphers is achieved by the Saber and CRYSTAL-Kyber variants for all security levels, regardless of the underlying computing power. The performance is comparable to that of the corresponding one achieved by a classical elliptic curve algorithm for key exchange for both RTT and packet loss ratio — i.e., the network parameters seem to have the same effect on post-quantum secure algorithms as in the case of a conventional elliptic curve algorithm. However, the effect of the network parameters on the performance is more crucial than the effect of the underlying chosen ciphers. Conclusion: According to the experiments, we conclude that there exist very promising algorithms that could be utilized in TLS in the near future, which may behave even better than the conventional elliptic curve algorithms for key exchange. It should also be pointed out that NIST announced on 5 July 2022 (i.e., after the completion of our research experiments) that, for general encryption used when we access secure websites, the CRYSTALS-Kyber algorithm has been selected, having as one of its advantages the speed of operation. Hence, the results of our paper are fully in line with the progress of the NIST process. Taking into account that the NIST process is still ongoing (now in its fourth round) with the aim to select more algorithms, as well as that some algorithms may be standardized outside NIST, it becomes evident that our results provide very useful insights on performance aspects of the post-quantum secure algorithms.

Can musical encryption be both? A survey of music-based ciphers

The purpose of this article is to analyze the characteristics of a range of music-based ciphers (from the fifteenth to twentieth centuries) with respect to their intended goals and actual outcomes. Historically, the practitioners of music-based ciphers generally fall into one of two distinct groups: composers and cryptographers. The primary goal of the composers was to create music that embedded extra-musical content by means of musico-alphabetic correspondences. The cryptographers were generally interested in presenting many varieties of cryptographic methods of which ciphers incorporating musical notes were a very small part. The systems used by the former were usually so superficial they should not really be considered encryption; whereas the systems used by the latter were so mechanical that most would not consider the results to be music. Musical encryption can rarely be both because the attributes needed for convincing musicality and strong encryption are not mutually conducive. However, after examining these music-based cryptosystems in detail, I will consider what criteria might be necessary to create a reasonably secure cipher which produces a normatively-musical output and apply these in the form of an original music-based cipher. For most of the ciphers, interactive web applications have been developed which render plaintext into enciphered melodies.

An efficient and secure cipher scheme for MIMO–OFDM systems based on physical layer security

An efficient and secure cipher scheme for MIMO–OFDM systems based on physical layer security

Improved Impossible Differentials and Zero-Correlation Linear Hulls of New Structure III

Impossible differential cryptanalysis and zero-correlation linear cryptanalysis are two kinds of most effective tools for evaluating the security of block ciphers. In those attacks, the core step is to construct a distinguisher as long as possible. In this paper, we focus on the security of New Structure III, which is a kind of block cipher structure with excellent resistance against differential and linear attacks. While the best previous result can only exploit one-round linear layer P to construct impossible differential and zero-correlation linear distinguishers, we try to exploit more rounds to find longer distinguishers. Combining the Miss-in-the-Middle strategy and the characteristic matrix method proposed at EUROCRYPT 2016, we could construct 23-round impossible differentials and zero-correlation linear hulls when the linear layer P satisfies some restricted conditions. To our knowledge, both of them are 1 round longer than the best previous works concerning the two cryptanalytical methods. Furthermore, to show the effectiveness of our distinguishers, the linear layer of the round function is specified to the permutation matrix of block cipher SKINNY which was proposed at CRYPTO 2016. Our results indicate that New Structure III has weaker resistance against impossible differential and zero-correlation linear attacks, though it possesses good differential and linear properties.