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.
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.
Development of Quantum Computers are growing rapidly, the security of today’s cryptographic systems which are working with Public Key Infrastructure (PKI) is at serious risk. RSA and ECC algorithms are the backbone of secure communication and digital identity can be breakable by quantum algorithms such as Shor’s. Hence, a transition is required to Post-Quantum Cryptography (PQC), which is designed to handle quantum attacks. This work provides a detailed review of how PQC can be integrated with the existing PKI, with a special focus on the auto-enrollment process. Auto-enrollment is an essential process but often overlooked mechanism, responsible for automatically issuing and renewing digital certificates. First, we explored how current PKI systems are exposed to the quantum threats and the readiness. The performance of the algorithms that are standardized by NIST, such as Kyber and Dilithium were discussed. We analyze the technical and operational challenges of transitioning to PQC by referencing both research studies and real-world implementations from major industry players such as Google and Microsoft. These include large key size, certificate size, compatibility issues, complex computations and need for crypto-agility. We also examine the hybrid approaches that combine classical and post-quantum methods as traditional strategies. The survey concludes by outlining best practices, deployment considerations, and open research challenges that must be addressed for a smooth, secure, and scalable shift to quantum-safe PKI. This work aims to guide researchers, engineers, and policymakers in building the next generation of cryptographic infrastructure that can stand the test-time even in a quantum world.
As quantum computing advances, current cryptographic protocols are increasingly vulnerable to quantum attacks, particularly those based on Public Key Infrastructure (PKI) like RSA or Elliptic Curve Cryptography (ECC). This paper presents a comprehensive review of Post-Quantum Cryptography (PQC) as a solution to protect digital systems in the quantum era. We provide an in-depth analysis of various quantum-resistant cryptographic algorithms, including lattice-based, code-based, hash-based, isogeny-based, and multivariate approaches. The review highlights the National Institute of Standards and Technology (NIST) PQC standardization process, highlighting key algorithms, such as CRYSTALS–Kyber, CRYSTALS–Dilithium, Falcon, and SPHINCS+, and discusses the strengths, vulnerabilities, and implementation challenges of the leading algorithms. In addition, we explore transition strategies for organizations, emphasizing hybrid cryptography to ensure backward compatibility during migration. This study offers key insights into the future of cryptographic standards and the critical steps necessary to prepare for the transition from classical to quantum-resistant systems.
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.
The impending arrival of viable quantum computing is a major worry to modern-day identity management systems that mainly depend on classical public-key cryptography techniques such as RSA and elliptic curve. Such systems are the basis of secure infrastructure in digital identities such as authentication, digital signature and trust models based on certificates. These cryptographic primitives can be broken using quantum algorithms like Shor and Grover, compromising the privacy of credentials and sessions stored and authenticated on digital ecosystems. The paper provides the necessity of the transition of identity management systems to post-quantum cryptographic (PQC) algorithms that will be resistant to quantum attacks. It gives a general overview of quantum-exposed identity protocols, as well as a look at the up-and-coming PQC algorithms under development, with a special call to digital signature algorithms capable of identity provision, authentication, and credential lifecycle management. Moreover, the paper isolates the problems of integration which include key size overhead, legacy system compatibility and performance trade-offs and suggests integration to take place through the use of hybrid and decentralized framework to allow a secure migration. This study will form part of a strategic plan to a post-quantum identity infrastructure, with the long term reliability, validity, and withstanding of quantum-era vulnerabilities.
The threats are existential to the traditional cryptosystems of public keys, including RSA, Diffie-Hellman, and elliptic curve cryptography (ECC), due to the rapid progress in quantum computing. Such algorithms as the Shor and Grover algorithms prove that as soon as large scale quantum computers are achieved, these classical cryptographic protocols will not provide any privacy and integrity to online communication. This has created an emergency to find post-quantum cryptography (PQC), or quantum-safe cryptography, which will resist attacks by both classical and quantum attackers. The paper is a review of the latest research and development in post-quantum cryptographic algorithms and their implementation in current security systems. We organize quantum-safe methods into significant organizations such as lattice-based, hash-based, multivariate polynomial-based and code-based encrypted communications. Each type has been evaluated critically based on computational efficiency, key sizes, speed of encryption/decryption and security proofs. The survey also examines the current standardization activities happening in the world and especially the U.S. National Institute of Standards and Technology (NIST) PQC competition, which lists candidate algorithms that have advanced to standard adoption. Besides this, the paper addresses hybrid cryptographic designs that use both classical and post-quantum bases in ensuring a seamless migration in the transition phase. Internet security protocols like TLS, VPNs and blockchain consensus as applications of PQC are examined in detail. Lastly, we pinpoint open research issues, which include creating lightweight PQC to support resource-constrained IoT devices, balancing performance and strong security assurances, and interoperability between the new PQC algorithms and existing infrastructures. Through detailed survey we inform the future of researchers, practitioners, and policymakers on the preparation of the post-quantum era of secure digital communications.
In 1994, Peter Shor developed a quantum algorithm that can efficiently solve the factorization and discrete logarithm problems. These problems are the foundation of modern cryptographic algorithms and the existence of an efficient algorithm for solving them threatens their security. Although large-scale quantum computers capable of breaking current cryptographic algorithms are not yet available, advances in quantum technology and the risk of “store now, decrypt later” attacks make it essential to prepare for migration to quantum-safe cryptography today. For the past decade, the cryptographic community has been actively developing algorithms that are not exploitable by Shor’s algorithm; such algorithms are said to be “quantum-safe” or “post-quantum.” However, cryptographic algorithms do not exist in isolation—they are components of larger cryptographic systems, such as protocols or other cryptographic primitives. Migrating these systems to use quantum-safe algorithms is therefore a complex task. This thesis studies the migration of several widely used cryptographic systems to post-quantum cryptography. In particular, we consider the migration of the public-key infrastructure (PKI), the TLS protocol, the XML Encryption and XML Signature standards, the SAML security framework, the Advanced Electronic Signature (AdES) standard, and the password-authenticated public-key encryption (PAPKE) primitive. For each topic, we analyze how the presence of quantum adversaries affects the security of existing constructions and identify components that rely on cryptographic assumptions vulnerable to quantum attacks. Based on this analysis, we propose approaches for adapting these systems to use post-quantum cryptographic algorithms. The proposed solutions are considered in two main forms: purely post-quantum and hybrid post-quantum. Purely post-quantum approaches rely exclusively on post-quantum algorithms, while hybrid post-quantum approaches combine classical and post-quantum mechanisms in order to provide security as long as at least one of the underlying assumptions remains secure. Hybrid post-quantum approaches are primarily motivated by uncertainty regarding the security of post-quantum algorithms. For each proposal, we discuss the advantages and disadvantages of the design, including deployment complexity, compatibility with existing systems, and performance considerations. In several cases, we also provide proof-of-concept implementations and evaluate their performance through benchmarks. We study post-quantum public-key infrastructures, which form a fundamental component of many other cryptographic systems. We show that constructing a purely post-quantum PKI does not fundamentally differ from constructing a classical PKI. For hybrid deployments, we propose two approaches—the composite hybrid and the parallel hybrid—which differ primarily in their implementation complexity. We also survey and analyze existing proposals for post-quantum TLS. In contrast, systems such as XML encryption and XML signatures, the SAML security framework, and the eIDAS-related AdES standard have received little attention in the context of post-quantum migration. For these systems, we outline possible migration approaches and provide proof-of-concept implementations. In addition, we present an example migration plan for a Trust Service Provider that relies on all of the discussed cryptographic systems, together with the methodology used to develop it. Finally, we consider the migration of the cryptographic primitive PAPKE. We propose a novel construction that replaces an ideal cipher with a half-ideal cipher, resulting in more efficient quantum-safe constructions and motivating the study of a new public-key encryption property called decryption robustness.