The advances in quantum computing present a threat to public key primitives due to their ability to solve hard cryptographic problems in polynomial time. To address this threat to critical Internet security protocols like the Transfer Layer Security (TLS), and Secure Shell (SSH), the National Institute of Standards and Technology (NIST) is currently working on the new generation of quantum-resistant key encapsulation and authentication schemes. In this paper, we evaluate protocol handshake performance when both post-quantum key exchange and authentication are integrated into TLS and SSH. Our experiments consider realistic network conditions and reveal that the introduced handshake latency ranges between 1-300% for TLS and 0.5-50% for SSH depending on the post-quantum algorithms used. In addition, we examine how the initial TCP window size affects post-quantum TLS and SSH performance, and show that even a small size increase can reduce the observed post-quantum slowdown by 50%. Finally, we discuss alternatives that can encourage the early adoption of post-quantum cryptography with minimum protocol performance degradation.
The advances in quantum computing present a threat to public key primitives due to their ability to solve hard cryptographic problems in polynomial time. To address this threat to critical Internet security protocols like the Transfer Layer Security (TLS), and Secure Shell (SSH), the National Institute of Standards and Technology (NIST) is currently working on the new generation of quantum-resistant key encapsulation and authentication schemes. In this paper, we evaluate protocol handshake performance when both post-quantum key exchange and authentication are integrated into TLS and SSH. Our experiments consider realistic network conditions and reveal that the introduced handshake latency ranges between 1-300% for TLS and 0.5-50% for SSH depending on the post-quantum algorithms used. In addition, we examine how the initial TCP window size affects post-quantum TLS and SSH performance, and show that even a small size increase can reduce the observed post-quantum slowdown by 50%. Finally, we discuss alternatives that can encourage the early adoption of post-quantum cryptography with minimum protocol performance degradation.
Quantum computing poses a critical threat to classical public-key cryptography, driving the adoption of post-quantum cryptography (PQC).While PQC performance has been extensively benchmarked in TLS, empirical studies on the Secure Shell (SSH) protocol remain limited.This paper evaluates the integration of PQC and hybrid (classical+PQC) mechanisms into SSH using an OQS-OpenSSH 8.9 prototype with liboqs support.We measured handshake latency, session size, and Secure Copy Protocol (SCP) transfer performance across standardized algorithms (CRYSTALS-Kyber, CRYSTALS Dilithium, Sphincs+), Falcon, and hybrid configurations.Experiments on heterogeneous legacy hardware under realistic LAN conditions were validated through Wireshark captures and protocol checklists.The results show that Falcon yields the smallest handshake sizes, Dilithium offers balanced and stable performance, Kyber scales predictably with NIST security levels, and Sphincs+ incurs significant overhead.Hybrid modes add limited cost while retaining classical trust anchors.These findings extend SSH PQC research beyond handshake analysis, offering deployment-oriented guidance for quantum-safe migration.
The emergence of quantum computing presents a significant threat to classical cryptographic primitives, particularly those employed in securing internet communications via widely used protocols such as Transport Layer Security (TLS). As conventional key exchange mechanisms will become increasingly vulnerable in the post-quantum era, the integration of post-quantum cryptographic (PQC) algorithms into existing security protocols is of utmost importance. This study investigates the impact of incorporating PQC key encapsulation mechanisms—specifically, the recent standards CRYSTALS-Kyber and HQC, in conjunction with the candidate standard BIKE—into the TLS 1.3 handshake. A comprehensive experimental evaluation was conducted to measure handshake latency under emulated network conditions with varying packet loss probabilities. The findings offer useful insights into the performance trade-offs introduced by PQC integration and further highlight the necessity of a timely transition to post-quantum cryptographic standards.
The advent of quantum computing poses significant threats to classical public-key cryptographic primitives such as RSA and elliptic-curve cryptography. As many critical network and security protocols depend on these primitives for key exchange and authentication, there is an urgent need to understand their quantum vulnerability and assess the progress made towards integrating post-quantum cryptography (PQC). This survey provides a detailed examination of nine widely deployed protocols - TLS, IPsec, BGP, DNSSEC, SSH, QUIC, OpenID Connect, OpenVPN, and Signal Protocol - analysing their cryptographic foundations, quantum risks, and the current state of PQC migration. We find that TLS and Signal lead the transition with hybrid post-quantum key exchange already deployed at scale, while IPsec and SSH have standardised mechanisms but lack widespread production adoption. DNSSEC and BGP face the most significant structural barriers, as post-quantum signature sizes conflict with fundamental protocol constraints. Across all protocols, key exchange proves consistently easier to migrate than authentication, and protocol-level limitations such as message size and fragmentation often dominate over raw algorithm performance. We also discuss experimental deployments and emerging standards that are shaping the path towards a quantum-resistant communication infrastructure.
Growing awareness of the impact of quantum threat on classical cryptography directly translates into a growing demand for accurate network simulation tools capable of estimating the integration effects of quantum-safe cryptography in current systems. In particular, the adoption of Post-Quantum Cryptography (PQC) has a direct impact on the performance of network endpoints and transmission overhead. This also affects the scalability of widely adopted security protocols such as TLS and SSH. In this paper, we present a throughput-oriented analytical model that provides a tight upper bound on the maximum sustainable rate of post-quantum secure connection establishment in TLS and SSH. This model takes into account both endpoint and network capacity constraints, decomposing the handshake process into dominant cryptographic operation time and network transmission time. Identifying the bottleneck allows us to derive the achievable throughput in terms of handshakes per second. The experimental results provided show the accuracy of the model against the data obtained from an experimental testbed using, among others, NIST standard primitives from FIPS 203, 204, and 205, including ML-KEM and ML-DSA. Finally, we integrate our model into a network environment and demonstrate how it can be leveraged to enable efficient resource allocation among multiple endpoints, optimizing PQC traffic in multiple-unicast scenarios.
Towards the end of the 20. century, quantum computing came into sight by the main effect of Shor's Algorithm. While this algorithm offers a solution for the factorization problem, which makes it exponentially faster, it alongside becomes a critical threat for the encryption schemes since mostly their security mechanisms rely on the difficulty of integer factorization or discrete log problems. Despite it is not known when advanced quantum computers will show up, yet, once it is developed, most existing cryptography will be rendered useless, which means all existing information security will be vulnerable. Owing to this risky situation, The National Institute of Standards and Technology (NIST) launched post-quantum cryptography (PQC) standardization process for the development of PQC schemes. In this paper, we have chosen three key encapsulation mechanisms and two digital signature algorithms with different parameter sets from the round three submissions. We measured their TLS 1.3 handshake performance using two resource-constrained devices and compared it to that of classical encryption and digital signature schemes. Experiment results showed that post-quantum algorithms come with an extra message overhead while their handshake delay values are promising.
The rapid advancement of quantum computing threatens the security foundations of today’s communication protocols. On the web, the traditional approach to securing web traffic has been to couple HTTP with TLS over TCP, but QUIC over UDP has recently emerged as an alternative to reduce latency and improve performance over unreliable networks. The need for an urgent transition to quantum-resistant web protocols demands further examination of both stacks. Consequently, in this work we evaluate their performance when combined with post-quantum primitives. To this end, we devise a practical evaluation framework that integrates the cryptographic primitives into TLS and QUIC implementations. Our analysis focuses on comparing the impact of hybrid and post-quantum primitives on TLS and QUIC under both ideal and realistic network conditions, providing quantitative insights into the performance cost and feasibility of transitioning toward a post-quantum web. Our results indicate that hybrid KEMs incur the highest handshake latency and bandwidth overhead, while pure post-quantum KEMs offer a favorable trade-off between security and performance, with only moderate costs. Moreover, QUIC consistently reduces the performance penalty of post-quantum primitives compared to TLS, especially in lossy network environments.