Post-Quantum Readiness: Why SMEs Must Harden Their Ingress Strategy Now

The era of “Harvest Now, Decrypt Later” has begun. While quantum computers capable of breaking commonly used asymmetric encryption methods like RSA or ECC are still in development, encrypted data streams are already being recorded by actors today. For German SMEs under the pressure of NIS-2 and DORA, Post-Quantum Cryptography (PQC) is no longer a futuristic scenario but an immediate requirement for digital sovereignty.

In 2026, the agility of infrastructure is the decisive security factor. Those using hardwired, outdated crypto stacks risk not only the loss of intellectual property but also their compliance capability. The solution lies in a hybrid migration strategy that combines classical methods with quantum-resistant algorithms without sacrificing the performance of the Cloud-Native infrastructure.

The Hybrid Approach: Kyber and Dilithium in the Ingress Layer

The most efficient lever for PQC readiness in the Kubernetes environment is the ingress layer. Instead of adapting each application individually, we focus on TLS termination at the edge. The current gold standard is the use of hybrid key exchange mechanisms (e.g., X25519 combined with Kyber-768).

By implementing OQS (Open Quantum Safe) extensions in Envoy-based ingress controllers or specialized API gateways, companies can already establish connections today that are protected against both classical attacks and future quantum computers. This hybrid mode ensures that legacy clients remain connected while modern probes already benefit from enhanced security.

Certificate Management and Crypto Agility with Cert-Manager

A central issue of PQC migration is the size of the new keys and signatures. Algorithms like Dilithium generate significantly larger certificates than RSA. This requires adjusting MTU sizes in vSwitches and validating buffer sizes in load balancer configurations.

Within the ayedo stack, we use the cert-manager in combination with dedicated PKI backends like HashiCorp Vault. To achieve post-quantum readiness, Certificate Signing Requests (CSRs) must be switched to new OID standards (Object Identifiers). Strategically, this means:

• Inventory: Recording all TLS endpoints.
• Abstraction: Decoupling crypto libraries from application logic.
• Automation: Automated rotation of hybrid certificates to mitigate the longer computation times during handshake validation.

Hardening Managed Apps: From Keycloak to Nextcloud

The migration does not end at the ingress. Internal service-to-service communication (East-West traffic) must gradually be switched to mTLS with PQC support. In a sovereign infrastructure, this means configuring tools like Keycloak for identity management to support token signatures that are long-term resistant.

For data-centric applications like Nextcloud or Vaultwarden in the ayedo catalog, “at-rest” encryption is secondary to “in-transit” security. Since we rely on open-source components, SMEs benefit from the rapid integration of PQ libraries (liboqs) into upstream projects, which provides a decisive advantage over proprietary black-box solutions where one depends on vendor patches.

Conclusion

Post-Quantum Readiness is not a binary state achieved by purchasing a product but a process of technological hardening. For SMEs, transitioning to a Cloud-Native infrastructure with ayedo offers the opportunity to establish crypto agility as a standard. By moving away from rigid hardware appliances to software-defined, open-source-based security architectures, you secure your data against the threats of tomorrow.

The next logical step in your security roadmap is auditing your current TLS termination. Let’s evaluate together how we can prepare your ingress stack for the post-RSA era.

FAQ: Post-Quantum Readiness in the Enterprise

1. Why should I invest now if quantum computers are not yet market-ready? The keyword is “Store now, decrypt later.” Attackers are storing encrypted traffic today to decrypt it in 5–10 years. Especially for sensitive design data or patient data in SMEs, the risk of a subsequent data leak is already real today.

2. Does Post-Quantum Cryptography slow down my applications? Yes, PQC algorithms are more computationally intensive, and the key sizes are larger. However, by using hardware acceleration and optimized ingress controllers (e.g., Envoy-based) in the ayedo stack, this overhead is minimized, so the user experience remains virtually unaffected.

3. Do I need to replace all my hardware? Typically not in a Cloud-Native environment. Since encryption is software-defined, an update of the ingress controllers and the crypto libraries used within the container images is usually sufficient.

4. Do common browsers already support post-quantum methods? Yes, leading browsers like Chrome and Firefox are already implementing hybrid methods (e.g., X25519MLKEM768). A correctly configured server infrastructure can already successfully negotiate these handshakes today.

5. How does ayedo specifically help with the PQC transition? We provide the necessary infrastructure expertise to transition your managed app stack (ArgoCD, Keycloak, etc.) to crypto-agile methods. We validate your TLS configurations and implement automated certificate processes that meet the requirements of NIS-2 and future standards.