COLUMN LEVEL ENCRYPTION
COLUMN LEVEL ENCRYPTION is a SQL statement in the Administration category. SQL Server: transparent column-level encryption with symmetric/asymmetric keys. The syntax is CREATE SYMMETRIC KEY key_name WITH ALGORITHM = AES_256 ENCRYPTION BY PASSWORD = 'password';. It returns encrypted column. A typical example: CREATE MASTER KEY ENCRYPTION BY PASSWORD = 'StrongPass123!'; CREATE CERTIFICATE SSN_CERT WITH SUBJECT = 'SSN Encryption Cert'; CREATE SYMMETRIC KEY SSN_KEY WITH ALGORITHM = AES_256 ENCRYPTION BY CERTIFICATE SSN_CERT; -- Add encrypted column: ALTER TABLE employees ADD encrypted_ssn VARBINARY(256); -- Encrypt: OPEN SYMMETRIC KEY SSN_KEY DECRYPTION BY CERTIFICATE SSN_CERT; UPDATE employees SET encrypted_ssn = EncryptByKey(Key_GUID('SSN_KEY'), '123-45-6789'); CLOSE SYMMETRIC KEY SSN_KEY; A close relative is CREATE USER, which creates a new database user account. A close relative is GRANT, which grants specific privileges (SELECT, INSERT, UPDATE, DELETE, ALL) to a user on a database/table. A close relative is REVOKE, which removes previously granted privileges from a user.