title: How to store the key used to encrypt files
body: <p>I'm playing around with an app to backup files to "the cloud" :) and I want to encrypt the files before I store them. That part I have covered, but as this app will be monitoring folders for change and uploading the changed files I need to store the key that I use to encrypt the files with. The idea is that the user provides a password and a key is generated.</p>
  
  <p>At the moment I'm using the .NET Framework to do the encryption. I'm using the RijndaelManaged class to encrypt/decrypt and the PasswordDeriveBytes class to get the key.</p>
  
  <p>But how should I keep the key that is used for encrypting the files? I also want the program start to with Windows and not need to have the user enter their password again.</p>