Blockchain wallets use two primary key generation schemes: non-deterministic (ND) and hierarchical deterministic (HD). ND key generation scheme provides better fund distribution but have issues with backup complexity and memory utilization. HD key generation scheme simplifies the backup process but is vulnerable to privilege escalation and brute-force attacks. In addition, deterministic pseudo-random algorithms used in these key generation schemes are predictable, which makes Quantum Random Number Generators (QRNGs) a promising alternative. This paper proposes Qwallet: a hybrid wallet based on the user's behavior that utilizes both HD and ND key generation architecture while leveraging QRNG to generate the keys. The wallet is optimized through deep learning, which trains on user behavior to select the optimal key generation scheme for maximum efficiency in blockchain wallet usage. We implemented and evaluated our proposed solution to support Ethereum transactions. Our results show that Qwallet reduces risk by up to 98% compared to traditional HD wallets, while consuming similar memory resources.
With the increasing interest for advanced protocols for Multi Party Computation, Fully-Homomorphic Encryption or Zero Knowledge proofs, a need for cryptographic algorithms with new constraints has emerged. These algorithms, called Arithmetization-Oriented ciphers, seek to minimize the number of field multiplications in large finite fields F2n or Fp. Among them, Ciminion is an encryption algorithm proposed by Dobraunig et al. in Eurocrypt 2021. In this paper, we show a new univariate modelization on a variant of Ciminion proposed by the designers. This instance restricts the attacker to at most 2 s/2 data, where s is the security level. Because the designers chose to reduce the number of rounds in that specific attacker model, we are able to attack the cipher for large security levels. We also propose some slight modifications of Ciminion that would overcome this vulnerability.
Abstract: This research paper surveys the landscape of cryptography, encompassing historical origins and modern applications. Beginning with foundational concepts, it explores encryption, decryption, ciphers, and keys, spanning symmetric and asymmetric cryptography. Historical context unfolds, tracing cryptography from ancient Egyptian hieroglyphs to Julius Caesar's cipher. The study then transitions to contemporary subjects. Elliptic Curves and Cryptography are investigated, showcasing their significance in secure communication, demonstrating ECC key exchange and AES-GCM encryption using python and Comparative analysis of ECC, RSA, and Diffie-Hellman sheds light on their performance. Zero-Knowledge Proofs are introduced as tools for privacy-preserving verification followed by an exploration of various Zero-Knowledge Proof (ZKP) protocols. By presenting practical implementation examples using Python, the paper illustrates how these proofs can be applied in real-world scenarios. Random Number Generation is examined and distinction between pseudorandom number generators (PRNGs) and cryptographically secure PRNGs (CSPRNGs) is emphasized conducting a thorough comparative analysis of PRNGs and CSPRNGs, considering factors like correlation, independence, periodicity, and entropy. Furthermore, the section evaluates the performance of different random number generation techniques. Fully Homomorphic Encryption emerges as a groundbreaking concept, discussing its mathematical properties, practical implementation, parameter selection, and optimization techniques enabling computation on encrypted data. Cryptographic Secret Sharing Schemes are explored for secure information distribution. The paper concludes by delving into the Chinese Remainder Theorem's applications within modern cryptographic protocols, particularly in RSA decryption and the integration factorization process of the RSA public key cryptosystem. It also provides a comprehensive overview of the theoretical foundations of primality testing, a pivotal aspect of the RSA algorithm. Overall, this research paper provides a comprehensive exploration of cryptography's historical context, core concepts, advanced techniques, and practical implementations, offering valuable insights into the realm of secure communication
In day-to-day life, everyone is concerned about their security and privacy, and their concern becomes more when it comes to transactions. The technology behind blockchain is quite young. Its efficiency and usefulness have led to claims that it may usher in a new era of breakthrough applications. Technology for digitally encrypting data transfers is fundamental to the blockchain's operation. Protecting the privacy of blockchain users and their transactions is crucial to the technology's success. Hash functions are a crucial component of the blockchain's underlying data structure, guaranteeing both its scalability and security. The blockchain's security may be assessed by analyzing the hash functions it employs in light of several security criteria. This article provides a primer on blockchain, covering such subjects as the technology's function, practical applications, and more. The cryptographic hash functions are introduced briefly, such as whirlpool, MD (message digest), RIPEMD, SHA (secure hash algorithm), BLAKE, etc. The paper concludes with the comparative results. Simulation results demonstrate that the different cryptographic hash algorithms outperform in terms of all the evaluation metrics, such as frequency and throughput.
Blockchain Technology Applications and Security
Chaos-based Image/Signal Encryption
Advanced Steganography and Watermarking Techniques
Fatma Hachicha, Yosra Ghabri, Khaled Guesmi, Ramzi Benkraiem
Cet article analyse la volatilité des cryptomonnaies à l’aide de la méthode de Monte-Carlo par chaînes de Markov (MCMC). L’objectif de cette étude est de trouver une technique plus efficace pour prévoir et estimer la volatilité, afin de fournir des informations cruciales aux gestionnaires de portefeuille et aux décideurs. Deux modèles ont été examinés : le modèle de volatilité stochastique autorégressive avec distribution t de Student (ARSV-t) et le modèle SVOL, en utilisant l’algorithme de Metropolis Hasting. Les résultats montrent que le modèle ARSV-t est plus performant que le modèle SVOL, surtout lorsqu’on traite des données financières hautement volatiles, telles que celles des cryptomonnaies. De plus, les prévisions obtenues avec le modèle ARSV-t sont plus précises que celles du modèle SVOL. Nous avons également constaté que la signification statistique des variables contrôlant la volatilité stochastique varie en fonction de la période d’estimation (COVID-19, guerre Russie-Ukraine). Ces résultats contribuent à améliorer notre compréhension des prévisions de la volatilité sur le marché des cryptomonnaies.
Abstract This chapter discusses the emergence of a lex financiera cryptographia, an ‘international financial and monetary law’ in the context of financial technology (FinTech), which is based on distributed ledger technology (DLT). DLT-based business models often bear characteristics of novelty and hybridity or otherwise sit uneasily within conventional legal and regulatory categories. The chapter also clarifies that the emerging concept of lex financiera as an international financial and monetary law that includes both hard and soft components that are enforced by a mix of national and international institutions. Moreover, this lex financiera cryptographia allows further discernment of the lex mercatoria that recognizes the inherent interconnectedness of normative domains. Thus, the lex financiera cryptographia emerges as a more concrete and and the development of a coherent body of encoded norms—whether those norms have a broader or a narrower relevance for international financial and monetary law.
Nowadays blockchain systems are widely used in many different fields, not only as a kind of payment method, i.e. cryptocurrency, but also as the infrastructure of decentralized applications. A smart contract, which is a program running on the blockchain, e.g. Ethereum, enables decentralized applications without the need for any trusted third party. To deploy a smart contract every miner of the blockchain needs to perform the same function of the smart contract such that they reach a consensus on its final state. Therefore, current blockchain systems are deterministic and non-probabilistic, disallowing any randomness in smart contracts, which is a significant limitation for the applicability of blockchains. A wide range of real-world applications depend on random functions, most obvious examples are games and lottery applications. Various methods have been proposed To address the random number generation problem, such as using a trusted oracle or the block hash. All of those have different disadvantages and advantages. Noticing the lack of concrete guidance for the inclusion of randomness in smart contracts on blockchains, we investigate the state-of-the-art random number generation methods and compare them in several critical aspects including availability, unpredictability, unbiasability, verifiability, scalability, execution time and cost.
Blockchain Technology Applications and Security
Chaos-based Image/Signal Encryption
Advanced Steganography and Watermarking Techniques
The problem of determining the position relationship between points and polygons is very extensive in practical applications. However, the existing solutions are only applicable to the case of convex polygons, and no solutions are given for arbitrary polygons. In addition, most of the existing schemes are carried out under the semi-honest model, and cannot resist the active attack of malicious adversaries. In order to solve these problems, this paper uses Paillier's encryption scheme, the idea of zero-knowledge proof to design a decision protocol to protect the position relationship between points and arbitrary polygons, which can not only prevent the deceptive behavior of malicious adversaries, but also extend the application from convex polygons to arbitrary polygons. A simulation example is used to prove that this paper is safe and efficient under the malicious model.
This paper explains the composition of the cryptocurrency wallet by analyzing a wallet’s components, functions, categories, the algorithm of signing, and security features as three major components used in the constitute of the cryptocurrency wallet, private key, public key, and address are introduced from their generation process with specific Elliptic Curve Digital Signature Algorithm secp256k1 and Keccak hash function. A variety of crypto wallets are divided into different categories by their purpose of use, the form of display, and Internet connectivity, and multiple crypto wallets are explained in the second part of this paper. The elliptic curve secp256k1 is selected in Ethereum for both calculating the public key information and performing signing transactions. This paper details secp256k1 and Keystore used behind the signing process and security of cryptocurrency wallet and outlines potential risks due to the development of computing power and transfer of validation system in Ethereum.
Open access
Chaos-based Image/Signal Encryption
Advanced Steganography and Watermarking Techniques
In recent years, cryptocurrencies, cryptoassets, electronic coins, tokens, non-fungible tokens, and other various terms for electronic assets have gained prodigious attention in the financial world. From the spike (and subsequent drop) in value of Bitcoin, to people spending millions of dollars on pixelated pictures of punks, the market for these assets has been extremely active despite its ups and downs. However, in addition to potential financial success via crypto markets, the development of crypto technology has allowed for a transformation of how individuals and institutions think of currency, financial security, and access to information Part I of this Comment explains what a cryptoasset is, as well as the current tax regime applicable to them. Part II defines like-kind exchanges and provides the historical context for the nonrecognition event. It also considers the IRS’s recent guidance pertaining to crypto like-kind exchanges. Part III puts forth this Comment’s main arguments for allowing crypto-for-crypto exchanges to qualify as like-kind exchanges.
Ethereum digital signatures have been found to make progress, but there has yet to be a consensus regarding their significance and process. Using digital signatures in Ethereum ensures the security of users' money and the Safety of their transportation. Elliptic Curve Digital Signature Algorithm (ECDSA), private key, and public key play an important role here. This paper analyzes the details of Ethereum's Digital Signature based on existing information. First, it explained the general background information about Ethereum. Send explain the ERC-20. ERC-20 are digital assets that represent value. They could become more compatible with the new standard and allow other features. Then digital signatures are explained in detail. This part included ECDSA, private key, and public key. ECDSA is the most critical algorithm during the production process. Private and public keys are the key features to ensure Safety. The last part is the Keystore file system. Using the Keystore file system, users can secure their private keys for their cryptocurrency wallets. To access their account, the user must have a password generated by them. The unencrypted files, on the other hand, create a vulnerability in the key store, which is exposed by these unencrypted files. Once an attacker obtains the user's unencrypted key, he cannot only take control of the account but also sign transactions on behalf of the user.
Summary Outsourcing storage and computation to cloud servers have become a trend. Although searchable symmetric encryption (SSE) had handled the data privacy issue caused by honest‐but‐curious servers, a semi‐honest server may return incomplete or incorrect results when users search for their encrypted data. To against such servers, scholars have recently used blockchain/Ethereum‐based SSE schemes which utilize the public, that is, active nodes, to verify the search process. However, the search operation in existing schemes is very expansive in terms of fee and time. In this paper, we propose a new blockchain‐based searchable encryption framework with search optimized, that is, free of charge, quicker, and more private, at the cost of some extra storage. Besides, we design a general and efficient verification algorithm for our framework, which makes the search verifiable. In addition, we deploy an instance of our framework on an official Ethereum test network, and the experimental results and evaluations demonstrate the advantage of our framework.
Manal Abdullah Alohali, Mohammed Aljebreen, Fuad Al-Mutiri, Mahmoud Othman · 8 authors
The real world is bounded by people, hospitals, industries, buildings, businesses, vehicles, cognitive cities, and billions of devices that offer various services and interact with the world. Recent technologies, including AR, VR, XR, and the digital twin concept, provide advanced solutions to create a new virtual world. Due to the ongoing development of information communication technologies and broadcast channels, data security has become a major concern. Blockchain (BC) technology is an open, decentralized, and transparent distributed database that can be maintained by the group. BC’s major features are high credibility, decentralization, transparency, versatility, autonomy, traceability, anonymity, intelligence, reward mechanisms, and irreversibility. This study presents a blockchain-driven image encryption technique using arithmetic optimization with a fractional-order Lorenz system (BDIE-AOFOLS). The BDIE-AOFOLS technique uses the FOLS method, which integrates the Arnold map, tent map, and fractional Lorenz system. Besides this, an arithmetic optimization algorithm (AOA) was carried out for the optimum key generation process to achieve the maximum PSNR value. The design of an AOA-based optimal generation of keys for the FOLS technique determines the novelty of the current work. Moreover, the cryptographical pixel values of the images can be stored securely in the BC, guaranteeing image security. We compared the outcomes of the proposed BDIE-AOFOLS technique against benchmark color images. The comparative analysis demonstrated the improved security efficiency of the BDIE-AOFOLS technique over other approaches, with a mean square error of 0.0430 and a peak signal-to-noise ratio of 61.80 dB.
Open access
Chaos-based Image/Signal Encryption
Advanced Steganography and Watermarking Techniques
Very recent attacks like ladder leak demonstrated feasibility to recover private key with side channel attacks using just one bit of secret nonce. ECDSA nonce bias can be exploited in many ways. Some attacks on ECDSA involve complicated Fourier analysis and lattice mathematics. In this paper will enable cryptographers to identify efficient ways in which ECDSA can be cracked on curves NIST256p, SECP256k1, NIST521p and weak nonce, kind of attacks that can crack ECDSA and how to protect yourself. Initially we begin with ECDSA signature to sign a message using private key and validate the generated signature using the shared public key. Then we use a nonce or a random value to randomize the generated signature. Every time we sign, a new verifiable random nonce value is created and way in which the intruder can discover the private key if the signer leaks any one of the nonce value. Then we use Lenstra–Lenstra–Lovasz (LLL) method as a black box, we will try to attack signatures generated from bad nonce or bad random number generator (RAG) on NIST256p, SECP256k1 curves. The analysis is performed by considering all the three curves for implementation of Elliptic Curve Digital Signature Algorithm (ECDSA).The comparative analysis for each of the selected curves in terms of computational time is done with leak of nonce and with Lenstra–Lenstra–Lovasz method to crack ECDSA. The average computational costs to break ECDSA with curves NIST256p, NIST521p and SECP256k1 are 0.016, 0.34, 0.46 respectively which is almost to zero depicts the strength of algorithm. The average computational costs to break ECDSA with curves SECP256K1 and NIST256p using LLL are 2.9 and 3.4 respectively.
Cryptocurrencies are considered to be big fastest growing players in the financial sector in the current scenario of the world. Many individuals, institutions, and corporate enterprises had invested heavily in this. In the last 5years, there is so much fluctuation in almost every crypto-currency price due to government regulations, public sentiment, media hype, and supply and demand of investors and users. So, We have decided to suggest cryptocurrency prices using deep learning techniques which make links between changes in the price of the cryptocurrency, their historical data, and other factors which will affect cryptocurrency price. We have also provided a technique which is suggesting a price of a few days in the future and helping in taking investment decisions about which cryptocurrencyis going to give more benefit in the future.Also, provide currency conversion techniques.
G. Sucharitha, V. Sitharamulu, Sachi Nandan Mohanty, Anjanna Matta · 5 authors
The use of encryption is essential to protect sensitive data, but it often poses challenges when it comes to locating and retrieving information without decryption. Searchable encryption provides an effective mechanism that achieves secure search over encrypted data. In this paper a new approach to address the fine-grained search and to protect sensitive data, Blockchain Assisted ciphertext policy decentralized attribute-based encryption (BA-CP-DABE) in cloud has been developed. The CP-DABE is employed to manage data access, secure key generation, while the immutability of blockchain ensures the confidentiality of ciphertext. By leveraging searchable encryption, it becomes possible to securely search encrypted data stored on the blockchain. Keywords are encrypted using attribute-based encryption and stored on a remote server, along with the corresponding ciphertext in the blockchain. One of the significant challenges in this approach is the assumptions-based technique i.e., bilinear mapping, which involves keyword ciphertext and trapdoor security. However, through extensive numerical experiments, the system has demonstrated its ability to generate key and trapdoor structures, as well as effectively find keywords within the encrypted data.
The article discusses the encryption security of the Bitcoin Core cryptocurrency wallet. Particular attention is paid to aspects of the practical implementation of cryptographic algorithms when encrypting the wallet.dat file with a password. The practical strongness to brute-force attacks using parallel computing on the GPU is also considered. It was found that Bitcoin Core did not implement an encryption key change for private keys. This implementation makes it possible to re-attack the wallet without knowing the new password, if it has already been compromised before. The changes to encryption algorithms that complicate the password brute force attacks on the GPU are also proposed.
Метою роботи є оптимізувати множення точок еліптичної кривої на скаляр за допомогою модернізованого метода “Подвійне скалярне множення з використанням трюку Штрауса-Шаміра з урахуванням Skew representation” та багато інших підходів. Ще однією метою роботи - зробити використання множення точок еліптичної кривої на скаляр безпечним в межах протоколу Zero-knowledge proof. З'ясувати, який метод множення буде найдешевшим в контексті визначеної метрики. Об’єктом дослідження є множення точок еліптичної кривої на скаляр в системі гаджет бібліотеках рекурсивних zk-Snark’s. Множення повинно виконуватися до стандартів протоколу Zero-knowledge proof. Також розглянуто варіанти практичного застосування описаних методів. У роботі виконане теоретичне та практичне дослідження, огляд алгоритмів та методів розв’язання задачі оптимізації з використанням різноманітних хитростей та підходів. Кодова база була написана мовою програмування Rust в бібліотеці franklin-crypto. Арифметизація, яка застосовується в бібліотеці – Plonkish та lookup table. Крива, яка була використана для тестування множення – Bn256. Ключові слова : точки еліптичної кривої, Zero-knowledge proof, мовою програмування Rust.