Disabling local authentication methods and allowing only Azure Active Directory Authentication improves security by ensuring that Azure MySQL flexible server can exclusively be accessed by Azure Active Directory identities.
The following 1 compliance controls are associated with this Policy definition 'Azure MySQL flexible server should have Azure Active Directory Only Authentication enabled' (40e85574-ef33-47e8-a854-7a65c7500560)
To complement access controls, data at rest should be protected against 'out of band' attacks (such as accessing underlying storage) using encryption. This helps ensure that attackers cannot easily read or modify the data.
Many Azure services have data at rest encryption enabled by default at the infrastructure layer using a service-managed key.
Where technically feasible and not enabled by default, you can enable data at rest encryption in the Azure services, or in your VMs for storage level, file level, or database level encryption.
**Implementation and additional context:**
Understand encryption at rest in Azure: https://docs.microsoft.com/azure/security/fundamentals/encryption-atrest#encryption-at-rest-in-microsoft-cloud-services
Data at rest double encryption in Azure: https://docs.microsoft.com/azure/security/fundamentals/encryption-models
Encryption model and key management table: