Post-Quantum Cryptography: An Introductory Overview and Implementation Challenges of Quantum-Resistant Algorithms

Cryptographic algorithms are an essential measure to ensure confidentiality and integrity of internet communication. The development of quantum computers (QCs) and their potential to utilize Shor’s Law, is increasingly recognized as a threat to asymmetric cryptography. In response, post-quantum cryptography (PQC) is gaining prominence as a notable field of research aiming to standardize quantum resistant algorithms before the operational usage of QCs. This paper is addressed to people with preliminary knowledge in the field of cryptography and QC. Based on a literature review, the authors provide an overview of challenges faced by the research community and elaborate the advancements in addressing post-quantum threats. A migration strategy from classical cryptosystems to PQC systems is in development, but obstacles such as time constraints and improper implementation complicate the process. Full implementation could take a decade or more. Until then, our paper aims to create awareness for potential challenges when transitioning towards PQC. As categorization scheme for these potential obstacles, we refer to a well- established model in cybersecurity – the McCumber Cube. Conclusions embrace preparing for risks of improper implementation and deriving a multi-step migration. Special attention is expected to be needed for data migration of existing data sets. As a request for future research in PQC, the authors identified the process of implementing post-cryptography standards, e.g., from the National Institute of Standards and Technology (NIST), and an assessment of the perceived readiness of industry to adapt.