Implement Always Encrypted

Always Encrypted is a comprehensive and powerful security feature provided by Microsoft Azure SQL Solutions. It ensures that sensitive data remains encrypted at all times—whether it’s in transit, stored in databases, or being processed by applications. By implementing Always Encrypted, organizations can enhance their data protection measures and comply with regulatory requirements.

Getting Started with Always Encrypted

To begin using Always Encrypted, you need to define an encryption key hierarchy. This hierarchy consists of a column master key, stored in an external key store, and one or more column encryption keys stored within the database. This separation of keys prevents unauthorized access to sensitive data by individuals with database access.

Once the key hierarchy is established, you can proceed to encrypt the desired columns in your database tables. This is achieved by configuring the columns as encrypted using the appropriate encryption type. Always Encrypted supports two encryption types:

1. Deterministic encryption: This type ensures that the same input value is always encrypted to the same encrypted value. It’s ideal for columns that require equality searches, grouping, or joins.
2. Randomized encryption: Unlike deterministic encryption, this type generates a different encrypted value for the same input every time. It’s suitable for columns that don’t require equality searches or grouping, such as sensitive notes or comments.

Here’s an example of encrypting columns using Transact-SQL:

CREATE TABLE Employees
(
EmployeeID int ENCRYPTED WITH (ENCRYPTION_TYPE = DETERMINISTIC,
ALGORITHM = 'AEAD_AES_256_CBC_HMAC_SHA_256',
COLUMN_ENCRYPTION_KEY = EmployeeKey,
ENCRYPTED_VALUE = [EmployeeID_Encrypted])
...
)

With the columns encrypted, you can perform operations on the data using normal Transact-SQL statements. The data is automatically decrypted when it’s returned to authorized applications or users, ensuring a seamless and transparent process.

Configuring Column-Level Access Control

To ensure that only authorized users can access the encrypted data, you need to configure column-level access control. This involves defining database roles and granting them the necessary permissions to access the column encryption keys. By managing access control diligently, you can maintain a strict security posture for your sensitive data.

Integration with Azure Services and Tools

Always Encrypted offers seamless integration with various Azure services and tools. For instance, you can leverage Azure Active Directory to authenticate users and restrict their access to encrypted data. Additionally, Azure Key Vault can be utilized as an external cryptographic key store to enhance security and compliance.

Safeguarding Sensitive Data with Always Encrypted

Implementing Always Encrypted is a critical step towards safeguarding sensitive data in your Azure SQL Solutions. By employing encryption and managing access control effectively, you can protect your data from unauthorized access, even in scenarios where your entire database may be compromised.