A virtual-optical based encryption model with the aid of public key infrastructure (PKI) is presented in this paper. The proposed model employs a hybrid architecture in which our previously published encryption method based on virtual-optics scheme (VOS) can be used to encipher and decipher data while an asymmetric algorithm, for example RSA, is applied for enciphering and deciphering the session key(s). The whole information security model is run under the framework of international standard ITU-T X.509 PKI, which is on basis of public-key cryptography and digital signatures. This PKI-based VOS security approach has additional features like confidentiality, authentication, and integrity for the purpose of data encryption under the environment of network. Numerical experiments prove the effectiveness of the method. The security of proposed model is briefly analyzed by examining some possible attacks from the viewpoint of a cryptanalysis.
A virtual-optical based encryption model with the aid of public key infrastructure (PKI) is presented in this paper. The proposed model employs a hybrid architecture in which our previously published encryption method based on virtual-optics scheme (VOS) can be used to encipher and decipher data while an asymmetric algorithm, for example RSA, is applied for enciphering and deciphering the session key(s). The whole information security model is run under the framework of international standard ITU-T X.509 PKI, which is on basis of public-key cryptography and digital signatures. This PKI-based VOS security approach has additional features like confidentiality, authentication, and integrity for the purpose of data encryption under the environment of network. Numerical experiments prove the effectiveness of the method. The security of proposed model is briefly analyzed by examining some possible attacks from the viewpoint of a cryptanalysis.
with the growing concerns of the current network security, development of hybrid cryptosystem based on the combination of optical symmetric cryptography and public key cryptography has aroused considerable research interest. In optical symmetry system, a new method for encrypting optical information using Fresnel lenses is proposed. The symmetry system’s keys include the focal length (f) and propagation wavelength (λ). Then, in public key cryptography, the key (λ,J) is encrypted by the RSA algorithm. Finally, we have implemented and result have been obtained using 12-level digital Fresnel lens by COMSOL Multiphysics to study of how the optical image deciphered the information using encryption keys. In addition, the main challenges and future prospects for the further development of hybrid cryptosystem system are discussed.
The emergence of quantum computing introduces unprecedented risks to classical cryptographic schemes, particularly digital signatures that safeguard authentication, confidentiality, and data integrity across digital ecosystems. To address these concerns, this paper investigates the adoption of Post-Quantum Cryptography (PQC) within Public Key Infrastructure (PKI) frameworks, emphasizing its role in strengthening electronic signature (eSign) systems against quantum threats. Traditional PKI implementations rely on algorithms such as RSA and ECC in combination with Hardware Security Modules (HSMs) for secure key management; however, these methods are vulnerable to quantum algorithms like Shor's. We examine how quantum-resistant alternatives-including lattice-based, hash-based, and multivariate polynomial-based schemes standardized by NIST-can be integrated into PKI without compromising interoperability and compliance. A comparative evaluation highlights trade-offs in performance, storage, and computational complexity while demonstrating the feasibility of embedding PQC into existing eSign infrastructures. Our findings underscore the urgency of transitioning towards quantum-safe digital signatures to ensure resilience, regulatory alignment, and long-term trust in national-scale digital services.
A hybrid encryption in the optical transform domain based on public key distribution system is proposed aiming at safely deliver and management of optical encrypted system.Frist,the original image is encrypted based on optical system,and then,the work key of optical system is compressed,finally,distribution and management of the compressed key is dong by public key distribution system.In the decryption stages,the receiver do not need to wait and can obtain dencryption key in advance by means of public key distribution system.The theoretical analysis and computer simulation results show that the proposed method can solve the problem of safely deliver and management and make good use of multi-dimensional keys that encrypted system of optical transform possess.Also,this method highlight advantage of hybrid system speed.
Digital signatures are indispensable for security on the Internet, because they guarantee authenticity, integrity, and non-repudiation, of namely e-mails, software updates, and in the Transport Layer Security (TLS) protocol which is used for secure data transfer, for example. Most signature schemes that are currently in use such as the RSA signature scheme, are considered secure as long as the integer factorization problem or the discrete logarithm (DL) problem are computationally hard. At present, no algorithms have yet been found to solve these problems on conventional computers in polynomial time. However, in 1997, Shor published a polynomial-time algorithm that uses quantum computation to solve the integer factorization and the DL problem. In particular, this means that RSA signatures are considered broken as soon as large-scale quantum computers exist. Due to significant advances in the area of quantum computing, it is reasonable to assume that within 20 years, quantum computers that are able to break the RSA scheme, could exist. In order to maintain authenticity, integrity, and non-repudiation of data, cryptographic schemes that cannot be broken by quantum attacks are required. In addition, these so-called post-quantum secure schemes should be sufficiently efficient to be suitable for all established applications. Furthermore, solutions enabling a timely and secure transition from classical to post-quantum schemes are needed. This thesis contributes to the above-mentioned transition. In this thesis, we present the two lattice-based digital signature schemes TESLA and qTESLA, whereby lattice-based cryptography is one of five approaches to construct post-quantum secure schemes. Furthermore, we prove that our signature schemes are secure as long as the so-called Learning With Errors (LWE) problem is computationally hard to solve. It is presumed that even quantum computers cannot solve the LWE problem in polynomial time. The security of our schemes is proven using security reductions. Since our reductions are tight and explicit, efficient instantiations are possible that provably guarantee a selected security level, as long as the corresponding LWE instance provides a certain hardness level. Since both our reductions (as proven in the quantum random oracle model) and instantiations, take into account quantum attackers, TESLA and qTESLA are considered post-quantum secure. Concurrently, the run-times for generating and verifying signatures of qTESLA are similar (or faster) than those of the RSA scheme. However, key and signature sizes of RSA are smaller than those of qTESLA. In order to protect both the theoretical signature schemes and their implementations against attacks, we analyze possible vulnerabilities against implementation attacks. In particular, cache-side-channel attacks resulting from observing the cache behavior and fault attacks, which recover secret information by actively disrupting the execution of an algorithm are focused. We present effective countermeasures for each implementation attack we found. Our analyses and countermeasures also influence the design and implementation of qTESLA. Although our schemes are considered (post-quantum) secure according to state-of-the-art LWE attacks, cryptanalysis of lattice-based schemes is still a relatively new field of research in comparison to RSA schemes. Hence, there is a lack of confidence in the concrete instantiations and their promised security levels. However, due to developments within the field of quantum computers, a transition to post-quantum secure solutions seems to be more urgently required than ever. To solve this dilemma, we present an approach to combine two schemes, e.g., qTESLA and the RSA signature scheme, so that the combination is secure as long as one of the two combined schemes is secure. We present several of such combiners to construct hybrid signature schemes and hybrid key encapsulation mechanisms to ensure both authenticity and confidentiality in our Public-Key Infrastructure (PKI). Lastly, we also demonstrate how to apply the resulting hybrid schemes in standards such as X.509 or TLS. To summarize, this work presents post-quantum secure candidates which can, using our hybrid schemes, add post-quantum security to the current classical security in our PKI.
Optical information security techniques are developed at a fast pace over the past two decades. In the present scenario, where enormous amount of data is being exchanged, information security plays an important role in protecting the information/data from unauthorized use/access. In this context, securing information using optical means has become relevant, given the suitable features of speed and multiple degrees of freedom that optical cryptosystems offer. Asymmetric cryptosystems have been introduced as an upgrade over the conventional double random phase encoding technique and they show resistance towards the known-plaintext attack. This paper reviews the symmetric and asymmetric cryptosystems and their attack analysis.
Quantum computing is developing quickly, and that's a big problem for traditional encryption techniques such as RSA and elliptic curve cryptography. Shor's algorithm, a quantum algorithm, specifically calls into question the long-term security that Public Key Infrastructures (PKIs) currently rely on. So, this thesis investigates how new post-quantum cryptography methods can be integrated into the public key infrastructure that businesses already use. This thesis examines the problems, both theoretical and practical, that arise when switching to cryptography resistant to quantum attacks. This thesis specifically examines how the NIST-selected algorithms, Kyber and Dilithium, are used in hybrid X.509 certificates that combine classical and post-quantum signatures.A test PKI environment was set up using OpenSSL-OQS and OpenXPKI to facilitate the testing process. Important PKI processes were examined in this setting, including TLS handshakes, certificate issuance, validation, and revocation. The results show that integrating PQC increases key and certificate sizes and also causes a moderate performance overhead. However, hybrid approaches offer a practical way to switch over. Lattice-based algorithms are particularly advantageous because they provide a strong balance of security, speed, and compatibility with existing systems. Using this information, a method was developed to help organizations gradually transition to a more secure system for managing their digital keys. This thesis connects advanced cryptography research with how businesses actually use it. It offers useful ideas and advice for companies getting ready for an age after quantum computing.