title: Strange result from DecryptByPassphrase
body: <p>I am trying encrypt and decrypt one column in table. My code is like this:</p>
  
  <pre><code>drop table EncryptString
  go
  create table EncryptString(db int, String varchar(100))
  go
  insert into EncryptString values (2, '123456789')
  go
  ALTER TABLE EncryptString
  ADD StringEncrypted varbinary(256); 
  GO
  
  declare @Pass nvarchar(512)
  set @Pass = 'somepassword'
  update EncryptString set StringEncrypted = ENCRYPTBYPASSPHRASE(@Pass, String, 1,                 convert( varbinary(128), db))
  where db = 2
  
  select * From EncryptString
  
  SELECT db, StringEncrypted 
  AS 'Encrypted String', CONVERT(nvarchar,
  DecryptByPassphrase('somepassword', StringEncrypted, 1 
  , CONVERT(varbinary, db)))
  AS 'Decrypted String' FROM EncryptString
  WHERE db = 2;
  </code></pre>
  
  <p>Why my 'Decrypted String' is like this:
  ㈱㐳㘵㠷9</p>
  
  <p>Thanks</p>