What are the differences between SQL Server encryption methods?

What are the differences between SQL Server encryption methods?

SQL Server offers several encryption methods, including Transparent Data Encryption (TDE), Always Encrypted, and cell-level encryption. TDE encrypts the entire database at rest, while Always Encrypted allows for encryption of specific columns, ensuring that sensitive data is never exposed in plaintext. Cell-level encryption provides more granular control but requires more management.

Can you explain how Transparent Data Encryption works?

Transparent Data Encryption (TDE) encrypts the database files and log files at the storage level. It uses a symmetric key called the database encryption key, which is protected by a certificate stored in the master database. TDE is transparent to applications, meaning no changes are needed in the application code.

What are the performance impacts of using encryption?

Using encryption can introduce some performance overhead, particularly with TDE, as it requires additional CPU resources for encryption and decryption processes. However, the impact is often minimal and can be mitigated with proper hardware and configuration.

Is Always Encrypted suitable for all types of data?

Always Encrypted is best suited for sensitive data, such as credit card numbers or personal identification information. However, it may not be ideal for all data types, especially if you need to perform operations on the encrypted columns, as it limits certain SQL operations.