Password Authenticated Key Exchange (PAKE) establishes secure communication channels using passwords for authentication. Currently, standardized PAKEs rely on classical asymmetric cryptography. However, these PAKEs may become insecure should the expected quantum threat become a reality. Despite the growing interest in realizing quantum-safe PAKEs, they did not receive much attention from the ongoing Post-Quantum Cryptography (PQC) integration efforts. Hence, there is a significant awareness gap compared to PQC primitives subject to the official standardization processes. We provide a comprehensive overview of existing PQC PAKEs, classify their design rationales and authentication methods, and address aspects related to their security and performance. We identify PAKE designs that are still unexplored in the PQC realm and discuss the possibility of their adaptation. Thus, we offer a detailed reference for future work on PQC PAKEs.
Password Authenticated Key Exchange (PAKE) establishes secure communication channels using passwords for authentication. Currently, standardized PAKEs rely on classical asymmetric cryptography. However, these PAKEs may become insecure should the expected quantum threat become a reality. Despite the growing interest in realizing quantum-safe PAKEs, they did not receive much attention from the ongoing Post-Quantum Cryptography (PQC) integration efforts. Hence, there is a significant awareness gap compared to PQC primitives subject to the official standardization processes. We provide a comprehensive overview of existing PQC PAKEs, classify their design rationales and authentication methods, and address aspects related to their security and performance. We identify PAKE designs that are still unexplored in the PQC realm and discuss the possibility of their adaptation. Thus, we offer a detailed reference for future work on PQC PAKEs.
The advancement of quantum computing technologies poses a significant threat to conventional public-key cryptographic systems such as RSA and Elliptic Curve Cryptography (ECC). Consequently, migration to Post-Quantum Cryptography (PQC) is becoming increasingly important in blockchain and Distributed Ledger Technology (DLT) environments, where long-term data integrity and public-key–based identity management require systematic migration strategies and corresponding standardization efforts. This paper analyzes standardization trends and technical structures for PQC migration in blockchain environments, focusing on the ITU-T SG17 draft standard X.qsdlt-ca. The study examines PQC application architectures and key cryptographic mechanisms across different blockchain types based on crypto-agility–driven phased migration strategies and identifies key technical considerations for standard design. In addition, considering growing user-centric authentication requirements in blockchain-based services, this paper proposes an extended framework for integrating PQC-based Password-Authenticated Key Exchange (PQC-PAKE) into blockchain environments. The framework is structured in terms of threat model, system components, message flows, and application scenarios, addressing security requirements of the user authentication layer that have received limited attention in existing PQC migration discussions. Finally, this study discusses future directions and technical challenges for blockchain PQC migration standards and presents design considerations for quantum-safe DLT systems.
The Password-Authenticated Key Exchange (PAKE) protocol is a useful tool for establishing secure remote communication between users, especially given the prevalence of amplifying a human-memorable password into a strong session key in the age of hand-held devices. Recent advances in quantum computing have stimulated interest in quantum-safe cryptographic schemes. Therefore, we propose QSPAK and QSPPK, two post-quantum and efficient PAKE protocols which are parallel extensions of PAK and PPK, but based on the hardness assumption over module lattices. Specifically, we make a comprehensive trade-off among multiple significant performance indicators such as the post-quantum security, the failure rate, the communication cost and the running time to guide optimal parameter choices. This rigorous instantiation has never been seen in previous PAKE papers. Additionally, utilizing the flexibility of module lattices, we provide three parameter sets (#1, #2, and #3) matching different security scenarios. We implement and benchmark QSPAK and QSPPK against other competitive proposals. The performance results indicate that our QSPAK and QSPPK, besides being more efficient, exhibit the flexibility and security advantages over the latter schemes. Furthermore, we construct a post-quantum password-authenticated TLS 1.3 framework, aimed towards provide a further suggestion for IETF standardization of quantum-safe PAKE.
Password authentication is a prevalent method of user verification across the Internet, and its use extends to scenarios where resources are limited. However, current password authentication protocols primarily rely on traditional password authenticated key exchange (PAKE) protocols (e.g., SRP, OPAQUE), which are vulnerable to attacks by quantum adversaries. To date, no efficient quantum algorithm has been found to solve the common challenges in lattice-based cryptography. Therefore, quantum-resistant PAKE protocols are generally built upon lattice-based cryptography. In this work, we propose a threshold verifiable oblivious pseudorandom function () protocol based on secret sharing. We then integrate it into a PAKE protocol and present an instantiation of a quantum-safe threshold PAKE protocol () based on the Ring Learning with Errors (RLWE) assumption. This integration gives our PAKE protocol resistance to precomputation attacks, similar to OPAQUE. Furthermore, by incorporating thresholding techniques into the PAKE protocol, we mitigate the risk of single points of failure on the server side. Our protocol not only preserves the security guarantees of traditional PAKE schemes but also resists attacks from quantum adversaries. We also provide a comprehensive security analysis and evaluation of, providing valuable insights for its practical implementation.
Transport Layer Security (TLS) protocols are essential for ensuring the confidentiality, integrity, and authentication of data communications. Mutual authentication between client and server is crucial in high-security scenarios such as finance and government. However, existing TLS protocols typically rely on certificate-based public key infrastructures (PKI) for client authentication, which increases deployment complexity and introduces risks associated with third-party trust. In contrast, password-authenticated TLS protocols use memorable passwords for client authentication, offering advantages in simplicity and usability. Nonetheless, such protocols remain vulnerable to server compromise and fail to provide sufficient security against quantum adversaries.To address these challenges, we propose a novel TLS protocol based on asymmetric password-authenticated key exchange (PAKE). The protocol employs an asymmetric PAKE mechanism wherein only password-derived information is stored on the server, while the client derives its private key from the password. This design effectively mitigates the risk of server leakage attacks. The protocol further integrates two types of post-quantum secure key encapsulation mechanisms (KEMs): an OW-ChCCA (One-Way Checkable against Chosen-Ciphertext Attacks) secure KEM for server key exchange and authentication, and an OW-PCA (One-Way Plaintext-Checkable Attacks) secure KEM for binding the client’s password-derived private key to enable client authentication. Both KEMs support multi-user, multi-challenge settings and admit tight, post-quantum secure instantiations.Furthermore, this paper provides a formal security analysis of the proposed protocol within an optimized multi-stage key exchange model. By combining the random oracle and ideal cipher models with a game-based proof methodology, we demonstrate that the protocol achieves mutual authentication and forward secrecy, while also providing tight security bounds and post-quantum resilience. This work thus presents a promising solution for constructing post-quantum password-authenticated TLS protocols.
Password-based authenticated key exchange (PAKE) allows participants sharing low-entropy passwords to agree on cryptographically strong session keys over insecure networks. In this paper, we present two PAKE protocols from lattices in the two-party and three-party settings, respectively, which can resist quantum attacks and achieve mutual authentication. The protocols in this paper achieve two rounds of communication by carefully utilizing the splittable properties of the underlying primitive, a CCA (Chosen-Ciphertext Attack)-secure public key encryption (PKE) scheme with associated nonadaptive approximate smooth projection hash (NA-ASPH) system. Compared with other related protocols, the proposed two-round PAKE protocols have relatively less communication and computation overhead. In particular, the two-round 3PAKE is more practical in large-scale communication systems.
Driven by advances in the standardization of NIST’s Post-Quantum Cryptography (PQC) algorithms, research on constructing Password Authenticated Key Exchange (PAKE) protocols using Key Encapsulation Mechanisms (KEMs) has gained considerable attention. Several PAKE protocols have established precise security requirements for the underlying KEM. Arriaga et al. introduced a PAKE protocol called CHIC, which requires the KEM to achieve anonymity under plaintext-checkable attacks (ANO-1PCA). An anonymous KEM does not leak any information about which public key was used for encryption. It protects the identities and privacy of participants and is critical in preventing identity-guessing attacks, therefore, anonymity is also called key-privacy. The anonymity of NIST PQC Round-3 candidates has recently been analyzed, some of which satisfied ANO-CCA.Huguenin-Dumittan and Vaudenay proposed two efficient constructions, TCHand TH, to create KEM from public-key encryption (PKE) schemes. Jiang et al. introduced TRHbased on TH. These constructions can transform any OW-CPA PKE into an IND-qCCA KEM efficiently and avoid re-encryption. However, prior to this work, no research has been conducted to determine whether these constructions preserve or lift anonymity.In this paper, we proved that for any OW-CPA, DS-IND PKE, the construction KEMRH= TRH[PKE,H] achieves ANO1-CCA in the quantum random oracle model (QROM). We then construct a KEM called KyberRH, and provide an algorithm for the CHIC protocol using KyberRH.