SQL Azure now supports Transparent Data Encryption with Bring Your Own Keys
I just stumbled upon an announcement from last month where Microsoft has released the preview of Transparent Data Encryption (TDE) with Bring Your Own Key (BYOK) support for Azure SQL Database and Azure SQL Data Warehouse! Now you can have control of the keys used for encryption at rest with TDE by storing these master keys in Azure Key Vault.
When you use TDE, your data is encrypted at rest with a symmetric key (called the database encryption key) stored in the database or data warehouse distribution. To protect this data encryption key (DEK) in the past, you could only use a certificate that the Azure SQL Service managed. Now, with BYOK support for TDE, you can protect the DEK with an asymmetric key that is stored in Key Vault. Key Vault is a highly available and scalable cloud-based key store which offers central key management, leverages FIPS 140-2 Level 2 validated hardware security modules (HSMs), and allows separation of management of keys and data, for additional security.
All the features of Azure SQL Database and SQL Data Warehouse will work with TDE with BYOK support, and you can start enabling TDE with a key from Key Vault today using Azure Portal, PowerShell, and REST API.