The general context Cryptography is a computer discipline that aims to protect messages through encryption systems. In symmetric cryptography, a secret parameter, called a key, is used both to encrypt and to decrypt messages. The security provided by a symmetric encryption system is evaluated using cryptanalysis techniques which aim, for example, to find the secret key. Quantum computer arrival could impact the cryptographic field. Indeed, in 1994, Shor exhibited that quantum computers could be used to improve assymetric cryptanalysis [17]. With the recent breakthrough in quantum computer, the security of cryptographic primitives against quantum adversary can not be taken as guaranteed. The NIST launched a competition for new primitives that are safe even against adversaries that has access to a quantum computer. To estimate the quantum security of a cryptographic scheme, it is necessary to perform its quantum cryptanalysis. Quantum cryptanalysis techniques sometimes are quantum adaptation of classical cryptanalysis techniques. This transformation is called quantizing. Let's note that an attack is valid if and only if it is more efficient than the naive attack. In the classical setting, the naive attack is the generic exhaustive search, in the quantum setting, it is the Grover search algorithm [14].
The general context Cryptography is a computer discipline that aims to protect messages through encryption systems. In symmetric cryptography, a secret parameter, called a key, is used both to encrypt and to decrypt messages. The security provided by a symmetric encryption system is evaluated using cryptanalysis techniques which aim, for example, to find the secret key. Quantum computer arrival could impact the cryptographic field. Indeed, in 1994, Shor exhibited that quantum computers could be used to improve assymetric cryptanalysis [17]. With the recent breakthrough in quantum computer, the security of cryptographic primitives against quantum adversary can not be taken as guaranteed. The NIST launched a competition for new primitives that are safe even against adversaries that has access to a quantum computer. To estimate the quantum security of a cryptographic scheme, it is necessary to perform its quantum cryptanalysis. Quantum cryptanalysis techniques sometimes are quantum adaptation of classical cryptanalysis techniques. This transformation is called quantizing. Let's note that an attack is valid if and only if it is more efficient than the naive attack. In the classical setting, the naive attack is the generic exhaustive search, in the quantum setting, it is the Grover search algorithm [14].
Quantum computers, that may become available one day, would impact many scientific fields, most notably cryptography since many asymmetric primitives are insecure against an adversary with quantum capabilities. Cryptographers are already anticipating this threat by proposing and studying a number of potentially quantum-safe alternatives for those primitives. On the other hand, symmetric primitives seem less vulnerable against quantum computing: the main known applicable result is Grover's algorithm that gives a quadratic speed-up for exhaustive search. In this work, we examine more closely the security of symmetric ciphers against quantum attacks. Since our trust in symmetric ciphers relies mostly on their ability to resist cryptanalysis techniques, we investigate quantum cryptanalysis techniques. More specifically, we consider quantum versions of differential and linear cryptanalysis. We show that it is usually possible to use quantum computations to obtain a quadratic speed-up for these attack techniques, but the situation must be nuanced: we don't get a quadratic speed-up for all variants of the attacks. This allows us to demonstrate the following non-intuitive result: the best attack in the classical world does not necessarily lead to the best quantum one. We give some examples of application on ciphers LAC and KLEIN. We also discuss the important difference between an adversary that can only perform quantum computations, and an adversary that can also make quantum queries to a keyed primitive.
Quantum computers, that may become available one day, would impact many scientific fields, most notably cryptography since many asymmetric primitives are insecure against an adversary with quantum capabilities. Cryptographers are already anticipating this threat by proposing and studying a number of potentially quantum-safe alternatives for those primitives. On the other hand, symmetric primitives seem less vulnerable against quantum computing: the main known applicable result is Grover’s algorithm that gives a quadratic speed-up for exhaustive search. In this work, we examine more closely the security of symmetric ciphers against quantum attacks. Since our trust in symmetric ciphers relies mostly on their ability to resist cryptanalysis techniques, we investigate quantum cryptanalysis techniques. More specifically, we consider quantum versions of differential and linear cryptanalysis. We show that it is usually possible to use quantum computations to obtain a quadratic speed-up for these attack techniques, but the situation must be nuanced: we don’t get a quadratic speed-up for all variants of the attacks. This allows us to demonstrate the following non-intuitive result: the best attack in the classical world does not necessarily lead to the best quantum one. We give some examples of application on ciphers LAC and KLEIN. We also discuss the important difference between an adversary that can only perform quantum computations, and an adversary that can also make quantum queries to a keyed primitive.
Motivated by Shor’s algorithm and its attractive features, the milestone results in quantum cryptanalysis were the discovery of quantum differential and linear cryptanalysis. In quantum cryptanalysis, quantum distinguishers imitate the classical setting. Details differ; however, as the distinguisher in the quantum setting can take maximum coset superposition of all possible subsets of plaintext pairs. Using quantum measurements, the winning gap of the game is exploited so that a distinguisher can still guess the secret key perfectly with a constant probability. Symmetric primitives also suffer reduced ideal security in the quantum world, but this security reduction is less drastic than for most asymmetric primitives. Stream ciphers, block ciphers, and cryptographic hash functions are primitives that are believed to resist quantum attacks. Analogs to Shor’s algorithm may say how hard it is to build a quantum computer, but devising quantum algorithms to outperform the best classical attacks for widely-used cryptographic primitives is probably outside the reach of current even if exponentially growing noisy intermediate-scale quantum (NISQ) computers.
This paper investigates the potential impact of quantum computing on the security of currently deployed cryptographic algorithms. The core premise is that the advent of powerful quantum computers, leveraging algorithms like Shor's algorithm and Grover's algorithm, poses a significant threat to widely used public-key cryptosystems and symmetric-key algorithms. We present a theoretical analysis of several key algorithms – RSA, ECC, and AES – examining their vulnerabilities when subjected to quantum attacks. Specifically, we explore the exponential speedup offered by Shor's algorithm for factoring large numbers, the impact on the key size of ECC, and the Grover's algorithm's influence on symmetric key search. Our work highlights the urgency of transitioning to post-quantum cryptography standards to mitigate the risks posed by this technological advancement. The goal is to provide a comprehensive understanding of the landscape of quantum cryptanalysis and its implications for the future of secure communication.
Cryptography, the practice of concealing messages for private exchange, has evolved significantly to address the challenges posed by new communication methods. In today`s digital world, cryptography has become the cornerstone of cybersecurity, using advanced mathematics like number theory and computational complexity to protect digital information through algorithms. The upcoming arrival of quantum computers poses a serious threat to traditional cryptographic methods, especially those based on asymmetric key cryptography. Quantum Safe Cryptography (QSC) represents the next step in information security, designed to develop cryptographic systems that can withstand attacks from both quantum and classical computers. As quantum computing moves from theory to reality, it`s becoming clear that current cryptographic methods based on integer factorization and discrete logarithm problems are vulnerable to quantum algorithms like Shor`s algorithm. This study highlights the security risks that quantum computing poses to existing encryption methods and proposes a comprehensive approach to quantum-safe cryptography. The transition to quantum-resistant algorithms involves replacing vulnerable cryptographic systems with alternatives that can resist quantum computational attacks. Current analysis shows that while asymmetric key cryptography faces immediate vulnerability, symmetric key algorithms and hash functions remain relatively secure in the near term with appropriate adjustments. Quantum cryptography, which directly uses quantum mechanical principles, offers highly secure encryption mechanisms, notably Quantum Key Distribution (QKD). This research aims to enhance the security of digital infrastructure against quantum threats by evaluating hybrid cryptographic implementations that combine classical and quantum-resistant approaches for optimal security.
Abstract It is viewed as revolutionary technology, offering incredible potential in terms of computing power within different scientific and industrial sectors. Quantum computers provide remarkable computing power; however, they also present significant security risks to existing public-key cryptography systems used to secure digital communication, online banking systems, government, medical applications, cloud computing systems, and IoT systems. Security of commonly used encryption schemes like RSA, DH, and ECC depends on mathematical problems that are impossible for classical computers to solve but can be easily resolved with the help of powerful enough quantum computers by using Shor’s algorithm. Furthermore, Grover’s algorithm makes exhaustive search attacks much faster, thus effectively lowering the security level of symmetric encryption schemes since it provides the speed-up for brute-force attacks. Post-Quantum Cryptography (PQC) turned out to be an effective and scalable method to protect digital data from attacks using quantum computing. In contrast to quantum cryptography, which requires a special quantum communication channel, PQC uses classical cryptographic algorithms that cannot be broken down by either classical or quantum computer due to certain mathematical problems. This research paper offers an extensive exploration of post-quantum cryptography through the analysis of the development of quantum computing, weaknesses of current cryptographic techniques, and mathematics behind quantum-resistant algorithms. Moreover, this paper explores the major classes of PQC techniques such as lattice-based, code-based, hash-based, multivariate, and isogeny-based cryptography and provides details about their security and application. Moreover, the report gives an overview of the NIST Post-Quantum Cryptography Standardization Project and analyzes recent standardizations of quantum-proof algorithms to be utilized in future digital infrastructures. Keywords: Post-Quantum Encryption, Quantum Security, Quantum-Proof Public-Key Cryptography, Lattice-Based Security Protocols, ML-KEM Key Encapsulation Mechanism, ML-DSA Digital Signature Algorithm, NIST Post-Quantum Cryptography, Contemporary Cybersecurity, Secure Communications, Cryptographic Algorithms.