Encrypts data with an asymmetric key.
Transact-SQL Syntax Conventions
EncryptByAsymKey ( Asym_Key_ID , { 'plaintext' | @plaintext } )
Is the ID of an asymmetric key in the database. int.
Is a string of data that will be encrypted with the asymmetric key.
Is a variable of type nvarchar, char, varchar, binary, varbinary, or nchar that contains data to be encrypted with the asymmetric key.
varbinary with a maximum size of 8,000 bytes.
Encryption and decryption with an asymmetric key is very costly compared with encryption and decryption with a symmetric key. We recommend that you not encrypt large datasets, such as user data in tables, using an asymmetric key. Instead, you should encrypt the data using a strong symmetric key and encrypt the symmetric key using an asymmetric key.
The following example encrypts the text stored in @cleartext with the asymmetric key JanainaAsymKey02. The encrypted data is inserted into the ProtectedData04 table.
@cleartext
JanainaAsymKey02
ProtectedData04
INSERT INTO [AdventureWorks].[Sales].[ProtectedData04] values( N'data encrypted by asymmetric key ''JanainaAsymKey02''', EncryptByAsymKey(AsymKey_ID('JanainaAsymKey02'), @cleartext) ) GO