The Internet Key Exchange Protocol Version 2 (IKEv2) underpins Internet Protocol Security (IPsec) by establishing secure associations and negotiating cryptographic keys. Its reliance on classical public-key primitives such as Elliptic Curve Diffie–Hellman (ECDH) renders it vulnerable to quantum attacks, as Shor’s algorithm can break these schemes once large-scale quantum computers become available. To address this challenge, we integrate post-quantum cryptography into IKEv2 using a hybrid key exchange combining ECDH over P-384 with the ML-KEM-768 parameter set of the Module-Lattice-Based Key-Encapsulation Mechanism (ML-KEM), following Request for Comments (RFC) 9370 and RFC 9242. We present a Fragmentation Boundary Model that identifies when post-quantum payloads approach or exceed the non-fragmenting IKE_SA_INIT payload budget across ML-KEM parameter sets, Internet Protocol (IP) versions, and effective path maximum transmission units (PMTUs). We implemented the hybrid design on a Texas Instruments TM4C1294 microcontroller running FreeRTOS and CycloneTCP, and measured its execution time, memory footprint, and network overhead. Across 150 successful handshakes per configuration, mean Security Association establishment time increased from 3390.4 to 3488.6 ms, an overhead of 98.2 ms (2.9%). Flash use increased by 8%, random-access memory (RAM) use by 5%, and total IKEv2 traffic size by 42%, while no IP fragmentation was observed under the evaluated Internet Protocol version 4 (IPv4) conditions. These findings establish the feasibility of the evaluated hybrid configuration on the TM4C1294 platform and provide a platform-specific baseline for further evaluation of quantum-resilient IPsec on embedded automotive architectures.
The Internet Key Exchange Protocol Version 2 (IKEv2) underpins Internet Protocol Security (IPsec) by establishing secure associations and negotiating cryptographic keys. Its reliance on classical public-key primitives such as Elliptic Curve Diffie–Hellman (ECDH) renders it vulnerable to quantum attacks, as Shor’s algorithm can break these schemes once large-scale quantum computers become available. To address this challenge, we integrate post-quantum cryptography into IKEv2 using a hybrid key exchange combining ECDH over P-384 with the ML-KEM-768 parameter set of the Module-Lattice-Based Key-Encapsulation Mechanism (ML-KEM), following Request for Comments (RFC) 9370 and RFC 9242. We present a Fragmentation Boundary Model that identifies when post-quantum payloads approach or exceed the non-fragmenting IKE_SA_INIT payload budget across ML-KEM parameter sets, Internet Protocol (IP) versions, and effective path maximum transmission units (PMTUs). We implemented the hybrid design on a Texas Instruments TM4C1294 microcontroller running FreeRTOS and CycloneTCP, and measured its execution time, memory footprint, and network overhead. Across 150 successful handshakes per configuration, mean Security Association establishment time increased from 3390.4 to 3488.6 ms, an overhead of 98.2 ms (2.9%). Flash use increased by 8%, random-access memory (RAM) use by 5%, and total IKEv2 traffic size by 42%, while no IP fragmentation was observed under the evaluated Internet Protocol version 4 (IPv4) conditions. These findings establish the feasibility of the evaluated hybrid configuration on the TM4C1294 platform and provide a platform-specific baseline for further evaluation of quantum-resilient IPsec on embedded automotive architectures.
Traditional public-key cryptography algorithms, such as Elliptic Curve Diffie-Hellman (ECDH), are vulnerable to quantum computing attacks. More critically, security protocols based on these algorithms are exposed to the “Harvest Now, Decrypt Later” threat, an ongoing risk that emphasizes the urgency of transitioning to post-quantum cryptography. This transition presents a significant challenge for lightweight security protocols, such as Ephemeral Diffie-Hellman over COSE (EDHOC), which are designed for IoT environments. To address this, a PQ/T hybrid key exchange construction for EDHOC is proposed, combining post-quantum mechanisms alongside traditional algorithms to mitigate future quantum threats while remaining secure against current threats using well-established classical cryptography. The scheme is evaluated on a CortexM4 processor, demonstrating the best performance with ML-KEM-512, with a slight increase in processing time, limited RAM overhead, and a roughly sevenfold increase in message size. Despite these trade-offs, the hybrid construction remains practical and represents a viable option for enhancing EDHOC security in anticipation of the post-quantum era in constrained environments.
A Virtual Private Network (VPN) ensures the confidentiality and integrity of data transferred between two endpoints, even if the means of transport are insecure. One popular protocol is Internet Protocol Security (IPSec) which operates at OSI layer 3 and protects all protocols at higher layers. Cryptographic keys in IPSec are negotiated using the Internet Key Exchange (IKE) protocol. IKE negotiates security parameters for IPSec sessions. In particular, the IKEv2 protocol uses the Elliptic Curve Diffie-Hellman (ECDH) algorithm to establish a secret key shared between two nodes on a network. Although solving such a problem remains difficult with current computing power, it is believed that generic quantum computers will be able to solve this problem, which implies that the security of IKEv2 is compromised. There are, however, several cryptographic systems that are trusted to be resistant to attacks by quantum computers. This family of cryptosystems is known as quantum-resistant cryptography (QRC). In this paper, after highlighting the requirements for a secure key exchange protocol, we briefly review the QRC solutions that have been proposed in the recent literature.
Abstract—The advent of fault-tolerant Cryptanalytically Relevant Quantum Computers (CRQCs) presents an existential threat to modern information security. Shor's polynomial-time quantum algorithm renders widely deployed public-key cryptographic primitives—including RSA, Diffie-Hellman (DH), and Elliptic Curve Cryptography (ECDH/ECDSA)—completely vulnerable to private key derivation. Furthermore, 'Harvest Now, Decrypt Later' (HNDL) adversarial campaigns actively intercept and store encrypted enterprise telemetry today, anticipating future quantum decryption capabilities. In response, the National Institute of Standards and Technology (NIST) finalized its primary Post-Quantum Cryptography (PQC) standards in FIPS 203 (ML-KEM), FIPS 204 (ML-DSA), and FIPS 205 (SLH-DSA). However, transitioning complex enterprise IT ecosystems to quantum-resistant primitives introduces severe architectural and computational disruptions: public key and signature sizes increase by several orders of magnitude, cryptographic handshake latencies escalate, network packets experience Maximum Transmission Unit (MTU) fragmentation, and legacy Hardware Security Modules (HSMs) lack microarchitectural support for lattice-based polynomial arithmetic. This paper provides an exhaustive, mathematically grounded technical survey and architectural roadmap for enterprise PQC migration. We formalize the Module Learning with Errors (M-LWE) and Module Short Integer Solution (M-SIS) hardness foundations, evaluate hybrid classical/post-quantum cryptographic transition models across standard transport protocols (TLS 1.3, IKEv2/IPsec, SSH), and formulate an enterprise Crypto-Agility Maturity Model. Furthermore, we construct an empirical enterprise testbed measuring throughput, connection establishment latency, memory footprints, and packet fragmentation across legacy and quantum-resistant suites. Our results show that while ML-KEM-768 achieves microsecond-level encapsulation, its 1,088-byte ciphertext expands TLS ClientHello payloads into multiple TCP segments under constrained networks. Finally, we establish open research directions in post-quantum identity federations, stateful hash signature tracking, and hardware-accelerated polynomial arithmetic. Index Terms—Post-Quantum Cryptography (PQC), FIPS 203 (ML-KEM), FIPS 204 (ML-DSA), Crypto-Agility, TLS 1.3, Lattice-Based Cryptography, Harvest Now Decrypt Later, Hardware Security Modules (HSM), Enterprise Migration.
The advent of quantum computing poses a significant threat to conventional public-key cryptographic systems, particularly resource-constrained mobile and cyber-physical environments. To address this challenge, this study proposes an implementation-oriented unified hybrid key derivation framework that integrates the Elliptic Curve Diffie–Hellman Ephemeral (ECDHE-P256) and post-quantum ML-KEM-768 algorithm for quantum-resilient secure communication. The proposed approach combines independently generated classical and post-quantum shared secrets through a lightweight mixing step followed by HKDF-SHA256 extraction and expansion to derive a unified 256-bit session key. This design preserves forward secrecy while enhancing resilience against quantum adversaries without requiring substantial modifications to the existing communication infrastructures. The framework was implemented on a heterogeneous testbed consisting of an x86_64 client and ARM64-based Android device. Experimental evaluations were conducted across 27 test configurations under three network latency conditions (50, 150, and 500 ms) using payload sizes of 64, 1024, and 10240 KB. Each configuration was executed for 1000 iterations to ensure statistically reliable measurements. The results demonstrate that, compared with standalone ECDHE-P256 and standalone ML-KEM-768, the proposed hybrid framework introduces only minimal computational overhead while maintaining stable resource utilization. Furthermore, network latency contributes more significantly to end-to-end communication delay than cryptographic processing overhead, indicating that the integration of classical and post-quantum cryptographic mechanisms does not constitute a major performance bottleneck. Overall, the proposed implementation-oriented framework provides a practical and lightweight transition strategy to quantum-resilient secure communication in heterogeneous mobile, IoT, and cyber-physical environments.
Within 1–2 decades, quantum computers may become powerful enough to break current public-key cryptography, prompting authorities such as the IETF and NIST to push for adopting quantum-resistant cryptography (QRC) in ecosystems like Internet Protocol Security (IPsec). Yet, IPsec struggles to adopt QRC, primarily because Internet Key Exchange Protocol Version 2 (IKEv2), which sets up IPsec sessions, cannot easily tolerate the large public keys and digital signatures of QRC. Many IETF RFCs have been proposed to integrate QRC into IKEv2, but their performance and interplay remain largely untested in practice. In this paper, we measure the performance of these RFCs over constrained links by developing a flexible, reproducible measurement testbed for IPsec with quantum-resistant IKEv2 proposals. Deploying our testbed in lossy wireless links and on the internationally distributed FABRIC testbed for Internet scenarios, we reveal that bottlenecks arise with quantum-resistant IKEv2 under high round-trip times, non-trivial packet loss, or other constraints. Our results, including the revelation of a 400–1000-fold increase in data overhead over high-loss wireless links, expose the shortcomings of today’s RFCs and call for further work in this vital area of post-quantum network security.
The emergence of quantum computing poses an existential threat to current Internet of Things security infrastructure, which relies predominantly on RSA and elliptic curve cryptography for confidentiality and authentication. Shor's algorithm enables polynomial-time factorization that can break these classical cryptographic primitives, necessitating urgent migration to quantum-resistant alternatives. This paper presents the first comprehensive performance evaluation of six NISTstandardized and candidate post-quantum key encapsulation mechanisms (ML-KEM-512, ML-KEM-768, NTRU-Prime-hrss, BIKE-L1, HQC-128, Classic-McEliece-348864) integrated into the MQTT protocol across 4,608 experimental configurations spanning diverse real-world network conditions. We systematically evaluate connection establishment latency, message delivery reliability, decryption computational overhead, and throughput stability under systematically varied network latency (10-150 ms representing LAN to satellite links), packet loss rates (0-10% spanning excellent to degraded connectivity), payload sizes (128-1024 bytes covering sensor telemetry to multimedia streams), and message transmission rates (1-10 Hz from periodic monitoring to real-time control). Statistical analysis of 622,080 MQTT messages totaling 384 hours of simulation time reveals that NTRU-Prime-hrss achieves optimal performance-security balance with 98.1% delivery ratio and 26.1 ms median handshake latency across all tested conditions, while Classic-McEliece exhibits 278.3 ms handshake overhead rendering it impractical for resourceconstrained deployments despite offering conservative security margins. We demonstrate through generalized linear modeling that transport-layer effects (TCP retransmissions, TLS record framing overhead) dominate post-quantum cryptographic computational costs, accounting for approximately 70% of endto-end latency in high-loss scenarios. Our novel three-gate decision framework provides quantitative deployment criteria for IoT operators balancing security requirements against operational constraints. Complete implementation, experimental dataset, and analysis scripts available at https://github.com/ vssk18/PQSM-RESEARCH.