With a recent increase in the advancement of the technology, computer system and it’s sensitive data are getting exhibited to unauthorised users, with steadily corroding the fundamentals of computer security. This, in fact, demanded fundamental innovations that require several cryptographic paradigms and security protocol. Previously it was thought that asymmetric cryptographic key like RSA, Diffie-Hellman, are very hard to decrypt by classical computation, but with the implementation of quantum computation, it is proved that this kind of cryptographic algorithm is very easy to decrypt and hackers can steal important Data [3], [6]. After the release of Ajtai’s research paper " Generating Hard Instances of Lattice Problem" [2], a million reasons arose in the minds of the researchers to develop on methods based on lattice-based cryptography to improve their security needs. Firstly, it provided much stronger security, and the average-case of several problems in lattice-based cryptography seems equivalent to the worst-case problem of these problems [2]. Moreover, lattices have the potential to persuade the cryptanalytic attacks created by any quantum computers i.e Quantum Computational Secure [3]. In this paper, we will discuss lattice-based cryptosystem, it’s security dimensions, a general brief on how it works, future scope, applications and areas of Interest.
With a recent increase in the advancement of the technology, computer system and it’s sensitive data are getting exhibited to unauthorised users, with steadily corroding the fundamentals of computer security. This, in fact, demanded fundamental innovations that require several cryptographic paradigms and security protocol. Previously it was thought that asymmetric cryptographic key like RSA, Diffie-Hellman, are very hard to decrypt by classical computation, but with the implementation of quantum computation, it is proved that this kind of cryptographic algorithm is very easy to decrypt and hackers can steal important Data [3], [6]. After the release of Ajtai’s research paper " Generating Hard Instances of Lattice Problem" [2], a million reasons arose in the minds of the researchers to develop on methods based on lattice-based cryptography to improve their security needs. Firstly, it provided much stronger security, and the average-case of several problems in lattice-based cryptography seems equivalent to the worst-case problem of these problems [2]. Moreover, lattices have the potential to persuade the cryptanalytic attacks created by any quantum computers i.e Quantum Computational Secure [3]. In this paper, we will discuss lattice-based cryptosystem, it’s security dimensions, a general brief on how it works, future scope, applications and areas of Interest.
The security of classical public-key cryptosystems, which operate based on the computational intractability of integer factorization and discrete logarithm problems, is profoundly threatened by the rapid development of quantum computing. Post-Quantum Cryptography (PQC) has been proposed to improve security against quantum attacks. Lattice-based cryptography is widely regarded as one of the most promising PQC method because of its proven security, efficient implementation, and functional versatility, and it has achieved significant progress in both algorithmic design and engineering implementation in recent years. This paper presents a systematic survey of the status of research on lattice-based cryptographic algorithms. First, the fundamental theory of lattices and their core hard problems are discussed. Next, the technical characteristics and performance of encryption and key encapsulation mechanisms, digital signature schemes, and key exchange protocols constructed based on lattice hard problems are reviewed and compared. Subsequently, the principles and optimization paths of two key technologies for lattice cryptography implementation, namely polynomial multiplication using the fast Number Theoretic Transform (NTT) and pre-image sampling algorithms, are discussed. Finally, considering the PQC standardization process of the National Institute of Standards and Technology (NIST), an outlook on future research directions for lattice-based cryptography is presented. The research directions include the development of more "succinct" fundamental hard problems, strengthening security proofs, improving algorithm efficiency, and countering novel attacks. This review serves as a reference for promoting the practical deployment and further research of lattice-based cryptography.
Quantum cryptography is a branch of cryptography that is a mixture of quantum mechanics and classical cryptography. The study of quantum cryptography is to design cryptographic algorithms and protocols that are against quantum computing attacks. In this chapter, the authors focus on analyzing characteristics of the quantum-proof cryptosystem and its applications in the future internet. Lattice-based cryptography provides a much stronger belief of security, in that the average-case of certain problems is equivalent to the worst-case of those problems. With the increase in cryptanalytic attacks conventional cryptographic schemes will soon become obsolete. As the reality of quantum computing approaches, these cryptosystems will need to be replaced with efficient quantum-resistant cryptosystems. We need an alternate security mechanism which is as hard as the existing number theoretic approaches. In this chapter, the authors discuss the security dimension of lattice-based cryptography whose strength lies in the hardness of lattice problems and also study its application areas.
Why study Lattice-based Cryptography? There are a few ways to answer this question. 1. It is useful to have cryptosystems that are based on a variety of hard computational problems so the different cryptosystems are not all vulnerable in the same way. 2. The computational aspects of lattice-based cryptosystem are usually simple to understand and fairly easy to implement in practice. 3. Lattice-based cryptosystems have lower encryption/decryption computational complexities compared to popular cryptosystems that are based on the integer factorisation or the discrete logarithm problems. 4. Lattice-based cryptosystems enjoy strong worst-case hardness security proofs based on approximate versions of known NP-hard lattice problems. 5. Lattice-based cryptosystems are believed to be good candidates for post-quantum cryptography, since there are currently no known quantum algorithms for solving lattice problems that perform significantly better than the best-known classical (non-quantum) algorithms, unlike for integer factorisation and (elliptic curve) discrete logarithm problems. 6. Last but not least, interesting structures in lattice problems have led to significant advances in Homomorphic Encryption, a new research area with wide-ranging applications.
Lattice cryptography has become one of the focal points in the era of quantum computing development. RSA and ECC, traditional public key cryptosystems, may become insecure in the face of quantum computers. In contrast, lattice cryptography is considered a potential solution for cryptographic security in the quantum computing age due to its inherent mathematical problems that require the use of quantum computers to solve. Moreover, lattice cryptographic algorithms can achieve efficient encryption and decryption processes and support a variety of cryptographic constructions, including encryption, signatures, and fully homomorphic encryption (FHE). With its high efficiency, multifunctionality, and high security, lattice cryptography has applications in various fields such as finance, e-commerce, government agencies, military, and network communications. It has also become one of the top contenders for the post-quantum cryptographic algorithm standards that have been recognized by the National Institute of Standards and Technology (NIST). This paper discusses the main contributions of lattice cryptography to society and its potential future development directions, as well as the challenges it may face and potential solutions. This thesis elaborates on lattice-based cryptography and comprehensively discusses the key technologies of lattice cryptography, its applications, security analysis, performance evaluation, and the latest progress.
Objective: Quantum algorithm are stronger and more secure than the classical computers not because they run on faster harder computers but also, they require fewer steps. With Quantum computers the attackers have high computing power and with quantum algorithm can easily break the cryptographic system. Lattice is regularly spaced grid of points stretching to infinity. Quantum safe security algorithms are resistant to both attacks caused by classical computers and the attack caused by quantum computers. Lattice based cryptography are the post quantum cryptographic standards which are resistant to the attacks from quantum computers hence has advantage of strong security and high efficiency. The main objective of the paper is to study lattice, lattice properties, lattice – based cryptographic algorithm to design new lattice based cryptographic algorithm which are quantum resistant in future. Methods: In this paper the lattice-based cryptography is discussed right from its seminal work to its efficient cryptographic schemes. Paper discusses what is lattice, lattice properties, lattice problem and algorithmic solution to lattice problem and lattice-based cryptography. Findings: After studying post quantum cryptographic algorithms using lattice it was found that lattice-based post quantum cryptographic algorithms are resistant to quantum computer attacks. Novelty: Paper discusses lattice, properties of lattice in a simple way. Widely used cryptographic algorithms like RSA, Diffie-Hellman Key exchange, Elliptic Curve Cryptography are not resistant to quantum computers attacks. Paper discusses the importance of post quantum algorithm using lattice that are resistant to quantum computer attacks.
Alongside the growth of technology is the increasing demand for security of data and communication channels. As attacking power grows, devices become smaller and data expands, the security needs to be stronger yet less resource-consuming than ever before. Public key cryptography (PKC) is used in the majority of today's communications systems. The security of public-key cryptographic schemes, such as RSA and elliptic curve cryptography (ECC), is based on underlying mathematical problems such as factoring large integers or solving the discrete log problem. However, the discovery of Shor's Algorithm in 1994 insinuates that these schemes will be insecure when a full-scale quantum computer is developed, as these problems will be solvable in polynomial time. Therefore attention has moved towards post-quantum, or quantum-safe, cryptography (QSC). In 2016, the National Institute of Standards and Technology (NIST) announced the beginning of their efforts to migrate to QSC, a standardisation process which has involved the cryptographic community worldwide. There are five main types of QSC being considered for standardisation; lattice-based, code-based, multivariate-based, hash-based and isogeny-based. Lattice-based cryptography (LBC) offers a promising alternative to today's classical approaches. Hard problems based on lattices are believed to be unsolvable, even by a quantum-computer, in a feasible amount of time. In 1995, Ajtai showed that the average case complexity of these problems is at least as hard as solving the problems in the worst case. Furthermore, lattice-based schemes are the only remaining contender in the NIST process to provide the important primitives of encryption, key encapsulation and digital signature schemes (DSSs). A well-recognised open problem surrounding quantum-safe cryptography is its increase in bandwidth and computational complexity in comparison to existing cryptography. However, in comparison to other quantum-safe schemes, LBC has been shown to be relatively efficient. In this thesis, novel software designs of lattice-based schemes are presented and shown to be competitive with existing PKC. Additionally, physical attacks are considered and countermeasures are incorporated into the designs. DSSs are required for authentication, integrity and non-repudiation of data. This thesis provides an evaluation of three leading signature schemes, BLISS-B, Dilithium and \textsc{Falcon}, which vary in terms of their key features, such as the sampling processes used, and the structure of the lattices. Physical attacks on the three schemes are considered and the effect on performance of appropriate attack countermeasures is evaluated. A novel fault attack on the NIST candidate \textsc{Falcon} is also proposed. A further advantage of LBC is the ability to support cryptographic primitives with extended capabilities to facilitate certificate management and compute on encrypted data. The complexity of today's technology advances mean applications require more sophisticated primitives, which contrastingly are required to run on even smaller platforms. This thesis presents novel quantum-safe advanced cryptographic schemes, specifically lattice-based identity-based encryption (IBE) and hierarchical identity-based encryption (HIBE). IBE removes the need for certificate management, as a user's public key depends on their public identity. IBE is currently used in vital applications such as emergency services communication and so the development of a high-performance quantum-safe alternative is imperative. This thesis also introduces the first scalable HIBE scheme based on lattices. The first HIBE scheme based on structured lattices, Latte, was proposed by the National Centre for Cyber Security (NCSC) in 2017. However, the public key and ciphertext sizes increased with each delegation and hence it was not feasible to scale the algorithm. Skinny Latte, proposed in this thesis, remedies this issue by fixing the dimension of the lattice, thereby making public key and ciphertext sizes constant. This research also shows that it is practical for real-world deployment. Overall, this thesis demonstrates that lattice-based cryptography is practical for real-world applications. It considers both theoretical and physical attacks, and presents novel designs of advanced quantum-safe cryptographic primitives, which have only yet been realised by lattices.