Server-side encryption (SSE) protects your data and helps you meet your organizational security and compliance commitments. SSE automatically encrypts your data stored on managed disks in Azure (OS and data disks) at rest by default when persisting it to the cloud. Learn more about Disk Encryption on Azure. Within DevTest Labs, all OS disks and data disks created as part of a lab are encrypted using platform-managed keys. As a lab owner you can now choose to encrypt lab virtual machine OS disks using your own keys. If you choose to manage encryption with your own keys, you can specify a customer-managed key to use for encrypting data in lab OS disks.
Learn more on encrypting your DevTest Lab OS disks