External Key Management in Managed HSM

This article discusses the implementation of External Key Management (EKM) in Azure Managed HSM (MHSM), comparing it to previous solutions like External Key Store. It details the architecture where a cloud service uses MHSM to call an external proxy, which then communicates with a customer-managed HSM for key wrapping/unwrapping. The author warns about significant security risks, availability impacts, and operational overhead, advising against use unless absolutely necessary. The article includes a step-by-step flow of data encryption key handling and mentions using AI (vibe-coding) to create a proxy for testing. It is highly technical, focusing on cloud security, key management, and Azure services.