title: Passphrase, Salt and IV, do I need all of these?
body: <p>If I am using Rijndael CBC mode, I have no idea why we would need salt.
  My understanding is even if people know the password, but he cannot get the data without IV.
  So from my perspective, password + IV seem to be sufficent secure.</p>
  
  <p>Do I get anything wrong?</p>