title: How to encrypt/decrypt for storage of sensitive data (ASP.NET Web API project)
body: <p>I am currently developping a web service. As part of this web service, I am be able to securely store user password in a SQL DB, and be able to unencrypt password value to the end-user through HTTPS web service.</p>
  
  <p>It's the first time I have to deal with this requirement. I found many example based on symetric and/or asymetric encryption. However I don't understand to permanently store the password/key used to encrypt the data.</p>
  
  <p>For instance, if I do use a symetric encryption based on RijndaelManaged, how do I securely store the input parameters used for the encryption so that my web service can at a later time retrieve data for the SQL DB, and unencrypt them.</p>