The answer lies in encryption, and this isn’t difficult. It can be done through the Firefox browser, as this tutorial in "Secure RSS Syndication" shows:
1. My content, which is going to sit inside the description element of an RSS feed, is going to be encrypted. We will actually put it inside a microformat.2. That feed [...]

Created your first podcast? Great! Your work isn’t over yet. Summarize your podcast and put the summary online with the download audio file. Think of the show notes as liner notes. They tell downloaders what to expect from the podcast and provide references to sources mentioned in the podcast.
The notes are a marketing tool too, [...]