David A. Wheeler's Java Security Tutorial (a briefing) is available here. Giving the entire tutorial takes about 2.5 hours. The tutorial is not public domain, but it is open source and licensed under the GPL.
The tutorial is available in PowerPoint (ppt) and Portable Document Format (PDF) formats.
You can contact David A. Wheeler at firstname.lastname@example.org.
You can see the rest of my website at http://www.dwheeler.com