AmphiKey, a dual-mode post-quantum/traditional (PQ/T) hybrid authenticated key exchange mechanism (AKEM) has been designed to secure smart grid communications against both classical and quantum threats. AmphiKey offers two distinct operational modes within a single framework: an Authenticated Mode and a Deniable Mode. The Authenticated Mode employs a blackbox approach, combining ephemeral ML-KEM-768 and X25519 with long-term Raccoon DSA keys to provide forward secrecy and strong, non-repudiable authenticity. This design achieves "OR" confidentiality, where security holds if either of the KEMs is unbroken, and robust "AND" authenticity. For the signature operation, it leverages the 'masking-friendly' Raccoon digital signature (DSA), which is specifically designed for side-channel attack resistance, though this protection is localized to the signing key and does not provide deniability. In contrast, Deniable Mode provides deniable authentication, preserving privacy. The protocol used ML-KEM-768 (AKEM-1), Ephemeral X25519 (AKEM-2), Raccoon-based DSA (Rac) (compared performance to ML-DSA-65), and the Ascon cipher to deliver its security guarantees. Key contributions include providing a flexible protocol with enhanced security, optional deniability, and efficiency adapted to the diverse needs of the smart grid infrastructure. We present a comprehensive performance evaluation on a heterogeneous testbed featuring a powerful server and client (AMD Ryzen 5) and a resource-constrained client (Raspberry Pi). In efficient Deniable mode, the full handshake completes in 0.15 ms on the server and 0.41 ms on the Raspberry Pi client. In contrast, the Authenticated Mode is bottlenecked by the client-side signature generation; the handshake takes 4.8 ms for the Raspberry Pi client to initiate and 0.84 ms for the server to verify.
AmphiKey, a dual-mode post-quantum/traditional (PQ/T) hybrid authenticated key exchange mechanism (AKEM) has been designed to secure smart grid communications against both classical and quantum threats. AmphiKey offers two distinct operational modes within a single framework: an Authenticated Mode and a Deniable Mode. The Authenticated Mode employs a blackbox approach, combining ephemeral ML-KEM-768 and X25519 with long-term Raccoon DSA keys to provide forward secrecy and strong, non-repudiable authenticity. This design achieves "OR" confidentiality, where security holds if either of the KEMs is unbroken, and robust "AND" authenticity. For the signature operation, it leverages the 'masking-friendly' Raccoon digital signature (DSA), which is specifically designed for side-channel attack resistance, though this protection is localized to the signing key and does not provide deniability. In contrast, Deniable Mode provides deniable authentication, preserving privacy. The protocol used ML-KEM-768 (AKEM-1), Ephemeral X25519 (AKEM-2), Raccoon-based DSA (Rac) (compared performance to ML-DSA-65), and the Ascon cipher to deliver its security guarantees. Key contributions include providing a flexible protocol with enhanced security, optional deniability, and efficiency adapted to the diverse needs of the smart grid infrastructure. We present a comprehensive performance evaluation on a heterogeneous testbed featuring a powerful server and client (AMD Ryzen 5) and a resource-constrained client (Raspberry Pi). In efficient Deniable mode, the full handshake completes in 0.15 ms on the server and 0.41 ms on the Raspberry Pi client. In contrast, the Authenticated Mode is bottlenecked by the client-side signature generation; the handshake takes 4.8 ms for the Raspberry Pi client to initiate and 0.84 ms for the server to verify.
Securing bandwidth-constrained Internet of Things (IoT) and edge networks during post-quantum migration creates an authentication trade-off: ML-KEM provides post-quantum key establishment, whereas post-quantum signatures increase certificate-chain size, verification cost, and handshake latency. We present HPQ-AKE, a sign-less hybrid authenticated key exchange for RSA-enabled IoT gateways and edge/cloud services that replaces transcript signatures with dual KEMs. HPQ-AKE combines ML-KEM-768 for post-quantum session secrecy and forward secrecy with RSA-OAEP for implicit mutual authentication, preserving existing RSA-enabled infrastructure during migration. We analyze HPQ-AKE in an extended Bellare-Rogaway model, separating classical authentication in the Random Oracle Model from session-key secrecy in the Quantum Random Oracle Model. Under the Module-LWE and RSA assumptions, it establishes AKE security, forward secrecy, and conditional KCI resistance under the long-term-key-only exposure assumptions. Evaluation combines x86 micro-benchmarking, analytical latency modeling, and 10,000-iteration Monte Carlo simulation. HPQ-AKE reduces modeled handshake transmission from 13,009 to 5,668 Bytes, a 56.4% reduction relative to a Hybrid TLS 1.3 Full handshake, while requiring 7.11 ms of total local computation on the measured x86 testbed. Under a simulated 50 kbps satellite-like link with 600 ms RTT and stochastic jitter, median latency is 1,914 ms, 31.4% below the 2,791 ms baseline. At 20 ms RTT, modeled break-even thresholds are 0.31 Mbps against the pre-cached baseline and 4.08 Mbps against the full baseline; both decrease as RTT increases. These x86-based results motivate evaluation on gateway-class IoT and edge platforms; performance on ARM gateways and unaccelerated microcontrollers remains unvalidated.
The increasing integration of smart grids within the Internet of Things (IoT) ecosystem requires the implementation of robust security measures due to vulnerabilities brought about by pervasive connectivity. Previous smart grid security protocols are based on classical cryptographic algorithms, which are susceptible to significant threats from emerging quantum computers. Consequently, the adoption of quantum-resistant solutions is imperative for the long-term security of smart grids. This article presents a novel protocol for authentication and secret key establishment in smart grids, utilizing post-quantum cryptography (PQC) algorithms. Our proposed protocol employs the FALCON digital signature algorithm for integrity verification and the CRYSTALS-Kyber key encapsulation mechanism (KEM) for secret key establishment, providing robust protection against quantum attacks. Our optimized implementation of the proposed protocol on a graphics processing unit (GPU) targets grid security module (GSM)/gateway-side deployments and demonstrates scalability under large numbers of concurrent authentication requests. Experimental validation demonstrates the proposed protocol’s ability to effectively manage numerous concurrent authentication requests, ensuring secure and efficient communication within smart grid networks.
Quantum computing threatens current public-key cryptography. New quantum-safe communication protocols are needed to address this threat. PQConnect is a tunnelling protocol designed for automated, end-to-end secure communication that resists quantum attacks while remaining compatible with existing infrastructure. It employs a hybrid handshake integrating classical and post-quantum primitives to establish shared keys. This thesis analyses PQConnect’s handshake, which uses a nested hybrid key exchange combining three schemes. It layers Classic McEliece (a code-based key encapsulation), X25519 (Curve25519 elliptic-curve Diffie–Hellman), and SNTRUP761 (Streamlined NTRU Prime) key encapsulations. These are being utilized as Key Encapsulation Mechanisms (KEMs). The layers are nested so that each inner exchange is concealed by outer layers, making any single layer difficult to break. The analysis details how each layer contributes to key establishment and how fresh ephemeral keys ensure forward secrecy. Additional PQConnect mechanisms are examined, including streaming verification of hand-shake data and DNS-based key distribution. Streaming verification processes large hand-shake records incrementally, reducing memory usage. For key distribution, PQConnect retrieves hashed server public keys via authenticated DNS records: a client fetches a hash of the server’s long-term key from DNS and verifies it before initiating the handshake, avoiding reliance on centralized certificates. A ratcheting key schedule derives new chain keys for each time epoch and per-packet encryption keys, limiting key exposure and extending forward secrecy beyond the initial handshake. For performance evaluation, packet-level traffic was captured using Wireshark for both PQConnect and traditional TLS sessions. Captured packets were analyzed to compare handshake flows and performance metrics such as packet size and total transmitted data. The results show that PQConnect introduces only a modest increase in packet sizes and overall data volume, with no significant latency overhead. Streaming verification and DNS-based lookup were confirmed to function correctly without noticeable delay. In conclusion, the study finds that PQConnect can establish quantum-secure tunnels with minimal performance penalty. Its hybrid handshake effectively integrates post-quantum primitives while maintaining compatibility with current infrastructure. DNS-based key distribution and streaming verification enhance trust and efficiency. The ratchet mechanism provides robust forward secrecy. These findings suggest that PQConnect is a practical and future-ready solution for secure tunnelling.
Introduction Session establishment, the process by which two parties authenticate each other and derive a shared secret key, forms the foundation for secure digital communication. Quantum computers threaten this foundation by breaking classical public-key primitives such as RSA and elliptic-curve Diffie–Hellman (ECDH), thereby enabling harvest-now–decrypt-later (HNDL) attacks that endanger long-term confidentiality. Methods This paper presents the design, implementation, and evaluation of an authenticated, quantum-resistant session protocol that replaces these vulnerable mechanisms with their post-quantum counterparts. The proposed protocol integrates ML-KEM-1024 (FIPS 203; CRYSTALS, Kyber) for ephemeral key exchange, ML-DSA-65 (FIPS 204; CRYSTALS, Dilithium) for endpoint authentication, and AES-256-GCM for symmetric protection. A transcript-bound HKDF–SHA3-256 key schedule and a 96-bit GCM nonce construction with conservative rekey limits are used to ensure forward secrecy, downgrade resistance, and message integrity. A Python/C prototype (PQClean ML-KEM-1024 with PyCryptodome AES-256-GCM) was benchmarked over 1,000 iterations on commodity hardware. Results The results show that sub-millisecond cryptographic overhead ML-KEM-1024 matches the performance of X25519 while vastly outperforming RSA-3072 in secure session establishment, and symmetric encryption remains cost effective. Nonces are unique 96-bit values, never reused across directions or beyond 2³² records, following NIST SP 800-38D; when nonce-misuse resistance is required, AES-256-GCM-SIV (RFC 8452) is supported as a drop-in alternative. Empirical tests under both local and WAN-emulated ( ≈ 40 ms RTT) network conditions confirm that the additional post-quantum cost maintains the handshake cryptographic latency in the 0.50–0.70 ms range. Discussion These results demonstrate that fully authenticated, forward-secure, quantum-resistant session negotiation is practical for real-world deployments.
The proliferation of Internet of Things (IoT) devices that use the Message Queuing Telemetry Transport (MQTT) protocol poses significant security challenges in the emerging quantum computing era. Current Transport Layer Security (TLS) implementations rely on classical cryptographic algorithms vulnerable to Shor's algorithm. This paper proposes PQ-MQTT, a hybrid post-quantum secure communication protocol that integrates ML-KEM-768 with X25519 for key encapsulation and a lightweight session-key derivation mechanism optimized for resource-constrained IoT publishers. We present a formal security analysis under the Quantum Random Oracle Model (QROM), demonstrating resilience against store-now-decryptlater attacks. Experimental evaluation on the Raspberry Pi 4, ESP32, and Arduino Nano 33 platforms shows that PQ-MQTT achieves handshake latencies of127.3ms,412.7ms, and1,847.2ms, respectively, with 18.2 KB of additional memory overhead. A comparative analysis of pure post-quantum and classical TLS implementations shows energy reductions of23.5%−40.5%relative to pure PQC, achieved through our hybrid optimization approach, while maintaining 94.2 % throughput efficiency.
The imminent advent of quantum computing threatens the long-term security of classical public-key cryptography, creating critical challenges for resource-constrained internet of things (IoT) environments.Hybrid cryptographic frameworks combining elliptic curve cryptography (ECC) with post-quantum cryptography (PQC) primitives have emerged as a transitional solution; however, their security properties remain insufficiently validated under semi-trusted infrastructure assumptions.This paper presents a comprehensive security evaluation of a hybrid ECC-KEM authentication and key agreement framework targeting IoT deployments.Using a dual-verification methodology that integrates formal symbolic analysis with the Tamarin-Prover and practical AI-assisted testing via the APSVer tool, we identify a critical impersonation vulnerability that enables a semi-trusted third party (TTP) to reconstruct PUF-based authentication material.To mitigate this flaw, we introduce a protocol enhancement incorporating ML-DSA post-quantum digital signatures and device-isolated key derivation.Formal verification confirms that the enhanced protocol achieves mutual authentication, session key secrecy, replay resistance, and effective isolation of the TTP.Experimental performance analysis demonstrates that the proposed security improvements introduce only a 12%-15% computational overhead, preserving feasibility for constrained IoT devices.The proposed framework provides a practical, quantum-resilient authentication architecture suitable for next-generation secure IoT deployments.