Dim rstream as new FileStream(Dateiname,FileMode.Open)
dim iv(5) as Byte
rstream.read(iv,0,rijndaelIvLength) as Byte
rd.IV = iv
rd.key=key
dim cs as new CryptoStream(rstream,rd.CreateDecryptor,CryptorStreamMode.read)
dim data (rstream.lenght - rijndaelIvLength)
dim i as Integer = cs.Read(data,0,data.lenght)

dim i as Integer = cs.Read(data,0,data.lenght)