Product : Microsoft Corp, Azure Stack/1903, IaaS + PaaS
Feature : Encryption (Data at Rest), CIA, Security & Compliance
Content Owner:  Bhagyashri (Shri) Bhagvat
Summary
All Azure Stack infrastructure and tenant data is encrypted at rest using BitLocker
Details
https://docs.microsoft.com/en-us/azure/azure-stack/azure-stack-security-foundations