I have a SharePoint 2010 web part that communicates with an external service. The external service provider gave us a secret cryptographic key that we must use to sign our requests. Currently, the key is hard-coded in our source code (we're still in the development). What are some good alternatives for storing this cryptographic key?
If the key were to be compromised, we could potentially experience service interruptions while we retrieved a new key from the service provider. So, not a huge deal, but if you know of a better way to store this secret key in SharePoint 2010, let me know.
[EDIT] The answer doesn't have to be specific to a cryptographic keys. For example, if the service provider gave us a password instead, where would I want to store that?