Post-Quantum Cryptography-Based Bidirectional Authentication Key Exchange Protocol and Industry Applications: A Case Study of Instant Messaging

Computer Science > Cryptography and Security [Submitted on 9 Apr 2026] Post-Quantum Cryptography-Based Bidirectional Authentication Key Exchange Protocol and Industry Applications: A Case Study of Instant Messaging Abel C. H. Chen, James W. H. Tung, Austin B. Y. Lin, Chin-Ling Chen, Ching-Chun Chang, Chin-Chen Chang This study aims to enhance the bidirectional authentication capability of ML-KEM (Module-Lattice-Based Key-Encapsulation Mechanism) by proposing the post-quantum cryptography-based (PQC-based) bidirectional authentication key exchange protocol. Furthermore, it introduces dual-usage certificates combining PQC-based DSA (Digital Signature Algorithm) and PQC-based KEM, which include composite schemes, catalyst schemes, and chameleon schemes. These dual-usage certificates utilize the PQC-based DSA public key and PQC-based KEM public key within the certificate to meet the requirements for bidirectional authentication and encryption, enabling the negotiation of a shared secret key. During the experimental phase, the study validates and compares key exchange message lengths and computation times under different certificate configurations. Finally, instant messaging is presented as an industry application to demonstrate the practical implementation of the proposed protocol. Comments: This study was presented at the NIST Workshop on Guidance for KEMs and is available at the following link: this https URL Subjects: Cryptography and Security (cs.CR); Networking and Internet Architecture (cs.NI) Cite as: arXiv:2604.08612 [cs.CR]   (or arXiv:2604.08612v1 [cs.CR] for this version)   https://doi.org/10.48550/arXiv.2604.08612 Focus to learn more Submission history From: Abel C. H. Chen [view email] [v1] Thu, 9 Apr 2026 00:32:56 UTC (463 KB) Access Paper: view license Current browse context: cs.CR < prev   |   next > new | recent | 2026-04 Change to browse by: cs cs.NI References & Citations NASA ADS Google Scholar Semantic Scholar Export BibTeX Citation Bookmark Bibliographic Tools Bibliographic and Citation Tools Bibliographic Explorer Toggle Bibliographic Explorer (What is the Explorer?) Connected Papers Toggle Connected Papers (What is Connected Papers?) Litmaps Toggle Litmaps (What is Litmaps?) scite.ai Toggle scite Smart Citations (What are Smart Citations?) Code, Data, Media Demos Related Papers About arXivLabs Which authors of this paper are endorsers? | Disable MathJax (What is MathJax?)