What is Always Encrypted in Azure SQL Database?

Always Encrypted is a feature designed to protect sensitive data, such as credit card numbers or national identification numbers (for example, U.S. social security numbers), stored in Azure SQL Database or SQL Server databases. Always Encrypted allows clients to encrypt sensitive data inside client applications and never reveal the encryption keys to the Database Engine (SQL Database or SQL Server). As a result, Always Encrypted provides a separation between those who own the data and can view it, and those who manage the data but should have no access. By ensuring on-premises database administrators, cloud database operators, or other high-privileged unauthorized users, can't access the encrypted data, Always Encrypted enables customers to confidently store sensitive data outside of their direct control. This allows organizations to store their data in Azure, and enable delegation of on-premises database administration to third parties, or to reduce security clearance requirements for their own DBA staff.