I'm attempting to build a browser-based HTML5 application that has the ability to store data locally on a PC (not mobile device) when offline. This data is sensitive and must be secure. Of course the trick is trying to find a way to be able to access the secure data with Javascript. I've ruled out browser local storage since its not secure. Could this be accomplished with a local database? If so, where could the DB credentials be stored? Javascript obviously doesn't seem like a good option to store them since its user-readable.