Managed HSM as a secure key storage option in Azure

Managed HSM (Hardware Security Module) is when you need the highest level of key protection in Azure. 

FIPS 140-3 Level 3 hardware is utilised.  

These are stringent security requirements set by NIST. They include: physical security through hardened enclosure and tamper-evident seals and active tamper-detection. The tamper detection includes detection of physical intrusion, temperature and voltage anomalies.