Question

I create my key using a certificate like this:

CREATE SYMMETRIC KEY some_Key_01
WITH ALGORITHM = AES_256
ENCRYPTION BY CERTIFICATE myCert;
GO

GRANT VIEW DEFINITION ON CERTIFICATE::myCert TO sqlUser;
GO

GRANT VIEW DEFINITION ON SYMMETRIC KEY::some_Key_01 TO sqlUser;
GO

Then I try to open and us it like this:

OPEN SYMMETRIC KEY some_Key_01
DECRYPTION BY CERTIFICATE myCert;
GO
SELECT CONVERT(datetime, DecryptByKey(EncryptedField))
AS 'DecryptedField'
FROM MyTable;
GO

But I get the message:
Msg 15151, Level 16, State 1, Line 23
Cannot find the certificate 'myCert', because it does not exist or you do not have permission.

Answer 1

You need to have the control permission on the certificate:

GRANT CONTROL ON CERTIFICATE::myCert TO sqlUser;
GO

And grant references permission on the key:

GRANT REFERENCES ON SYMMETRIC KEY::some_Key_01 TO sqlUser;
GO