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SignByAsymKey (Transact-SQL)

Signs plaintext with an asymmetric key

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SignByAsymKey(Asym_Key_ID,@plaintext [ ,'password' ] )


Is the ID of an asymmetric key in the current database. Asym_Key_ID isint.


Is a variable of type nvarchar, char, varchar, or nchar containing data that will be signed with the asymmetric key.


Is the password with which the private key is protected. password is nvarchar(128).

varbinary with a maximum size of 8,000 bytes.

Requires CONTROL permission on the asymmetric key.

The following example creates a table, SignedData04, in which to store plaintext and its signature. It next inserts a record in the table, signed with asymmetric key PrimeKey, which is first decrypted with password 'pGFD4bb925DGvbd2439587y'.

-- Create a table in which to store the data
CREATE TABLE [SignedData04]( Description nvarchar(max), Data nvarchar(max), DataSignature varbinary(8000) );
-- Store data together with its signature
DECLARE @clear_text_data nvarchar(max);
set @clear_text_data = N'Important numbers 2, 3, 5, 7, 11, 13, 17, 
      19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79,
      83, 89, 97';
INSERT INTO [SignedData04] 
    VALUES( N'data encrypted by asymmetric key ''PrimeKey''',
    @clear_text_data, SignByAsymKey( AsymKey_Id( 'PrimeKey' ),
    @clear_text_data, N'pGFD4bb925DGvbd2439587y' ));