CREATE COLUMN ENCRYPTION KEY (Transact-SQL)

Article
12/29/2022

Applies to: SQL Server 2016 (13.x) and later Azure SQL Database Azure SQL Managed Instance

Creates a column encryption key metadata object for Always Encrypted or Always Encrypted with secure enclaves. A column encryption key metadata object contains one or two encrypted values of a column encryption key that is used to encrypt data in a column. Each value is encrypted using a column master key.

Transact-SQL syntax conventions

Syntax

CREATE COLUMN ENCRYPTION KEY key_name   
WITH VALUES  
  (  
    COLUMN_MASTER_KEY = column_master_key_name,   
    ALGORITHM = 'algorithm_name',   
    ENCRYPTED_VALUE = varbinary_literal  
  )   
[, (  
    COLUMN_MASTER_KEY = column_master_key_name,   
    ALGORITHM = 'algorithm_name',   
    ENCRYPTED_VALUE = varbinary_literal  
  ) ]   
[;]

Arguments

key_name
Is the name by which the column encryption key will be known in the database.

column_master_key_name Specifies the name of the custom CMK used for encrypting the column encryption key.

algorithm_name
Name of the encryption algorithm used to encrypt the value of the column encryption key. The algorithm for the system providers must be RSA_OAEP.

varbinary_literal
The encrypted column encryption key value BLOB.

Warning

Never pass plaintext column encryption key values in this statement. Doing so will compromise the benefit of this feature.

Remarks

The CREATE COLUMN ENCRYPTION KEY statement must include at least one or two values. You can use the ALTER COLUMN ENCRYPTION KEY (Transact-SQL) to add a second value later. You can also use the ALTER COLUMN ENCRYPTION KEY statement to remove a value.

Typically, a column encryption key is created with just one encrypted value. At times, you need to rotate a column master key to replace the current column master key with the new column master key. When you need to rotate the key, add a new value of the column encryption key, encrypted with the new column master key. This rotation allows you to ensure client applications can access data encrypted with the column encryption key, while the new column master key is made available to client applications. An Always Encrypted enabled driver in a client application that doesn't have access to the new master key, will use the column encryption key value encrypted with the old column master key to access sensitive data.

The encryption algorithms, Always Encrypted supports, require the plaintext value to have 256 bits.

It is recommended you use tools, such as SQL Server Management Studio (SSMS) or PowerShell to manage column encryption keys. Such tools generate encrypted values and automatically issue CREATE COLUMN ENCRYPTION KEY statements to create column encryption key metadata object. See Provision Always Encrypted keys using SQL Server Management Studio and Provision Always Encrypted keys using PowerShell.

You can also generate a column encryption key value programmatically using a using a key store provider that encapsulates the key store holding the column master key. For more information, see Develop applications using Always Encrypted.

Use sys.columns (Transact-SQL), sys.column_encryption_keys (Transact-SQL), and sys.column_encryption_key_values (Transact-SQL) to view information about column encryption keys.

Permissions

Requires the ALTER ANY COLUMN ENCRYPTION KEY permission.

Examples

A. Creating a column encryption key

The following example creates a column encryption key called MyCEK.

CREATE COLUMN ENCRYPTION KEY MyCEK   
WITH VALUES  
(  
    COLUMN_MASTER_KEY = MyCMK,   
    ALGORITHM = 'RSA_OAEP',   
    ENCRYPTED_VALUE = 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
);  
GO

Creating a Column Encryption Key with Two Values

The following example creates a column encryption key called TwoValueCEK with two values.


CREATE COLUMN ENCRYPTION KEY TwoValueCEK   
WITH VALUES  
(  
    COLUMN_MASTER_KEY = CMK1,   
    ALGORITHM = 'RSA_OAEP',   
    ENCRYPTED_VALUE = 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
),  
(  
    COLUMN_MASTER_KEY = CMK2,   
    ALGORITHM = 'RSA_OAEP',   
    ENCRYPTED_VALUE = 0x016E000001630075007200720065006E00740075007300650072002F006D0079002F0064006500650063006200660034006100340031003000380034006200350033003200360066003200630062006200350030003600380065003900620061003000320030003600610037003800310066001DDA6134C3B73A90D349C8905782DD819B428162CF5B051639BA46EC69A7C8C8F81591A92C395711493B25DCBCCC57836E5B9F17A0713E840721D098F3F8E023ABCDFE2F6D8CC4339FC8F88630ED9EBADA5CA8EEAFA84164C1095B12AE161EABC1DF778C07F07D413AF1ED900F578FC00894BEE705EAC60F4A5090BBE09885D2EFE1C915F7B4C581D9CE3FDAB78ACF4829F85752E9FC985DEB8773889EE4A1945BD554724803A6F5DC0A2CD5EFE001ABED8D61E8449E4FAA9E4DD392DA8D292ECC6EB149E843E395CDE0F98D04940A28C4B05F747149B34A0BAEC04FFF3E304C84AF1FF81225E615B5F94E334378A0A888EF88F4E79F66CB377E3C21964AACB5049C08435FE84EEEF39D20A665C17E04898914A85B3DE23D56575EBC682D154F4F15C37723E04974DB370180A9A579BC84F6BC9B5E7C223E5CBEE721E57EE07EFDCC0A3257BBEBF9ADFFB00DBF7EF682EC1C4C47451438F90B4CF8DA709940F72CFDC91C6EB4E37B4ED7E2385B1FF71B28A1D2669FBEB18EA89F9D391D2FDDEA0ED362E6A591AC64EF4AE31CA8766C259ECB77D01A7F5C36B8418F91C1BEADDD4491C80F0016B66421B4B788C55127135DA2FA625FB7FD195FB40D90A6C67328602ECAF3EC4F5894BFD84A99EB4753BE0D22E0D4DE6A0ADFEDC80EB1B556749B4A8AD00E73B329C95827AB91C0256347E85E3C5FD6726D0E1FE82C925D3DF4A9  
);  
GO

Share via