Post-Quantum Interoperability in Action: How Collaboration Is Shaping the PQC Future of Cybersecurity

As the cryptographic community rallies behind NIST's post-quantum cryptography (PQC) standardization, one truth is becoming clear: PQC won't succeed in isolation. It must interoperate — across algorithms, libraries, protocols, and real-world infrastructure. We have embraced this challenge head-on by creating a living interoperability tracker — continuously testing PQC integration across solutions and open-source projects like EJBCA, SignServer, and Bouncy Castle. Working in collaboration with projects such as OpenSSL, WolfSSL, and leading HSM vendors, our goal is clear: to demonstrate that post-quantum cryptography isn’t just theoretical — it’s practical and working today. This talk will share concrete results from our testing across TLS 1.3, CMS, hybrid certificates, and Hardware Security Modules (HSM) integrations — using LMS, ML-DSA, ML-KEM, and SLH-DSA. We’ll highlight what worked, what broke, and what we’re learning about making PQC truly usable at scale. Most importantly, we’ll explore how collaboration — with OpenSSL maintainers, IETF hackathons, and standards bodies — is critical to ensuring that the next generation of cryptography is not only secure, but interoperable and practical. We’ll provide practical configuration examples and open-source tools for those ready to start their own PQC journey.