You cite Camtasia as a source of concern. This is a screen capture app and there are many others like it such as ScreenFlow. Even the free QuickTime Player X can now capture the screen. So, would I be correct in assuming that your presentations are delivered to computer screens as in a webinar or conference app such as Bb Collaborate, Adobe Connect etc.?
If that's the case, then there is little one can do beyond moral suasion and copyright saber rattling. Members of the audience can record the presentation as a video file, not a Keynote file. Thus, they don't have access to the specific assets that make up your presentation nor the techniques you used to combine them as you did. They have only what was audible and visible.
If that's not the case, perhaps you can provide more details on how your audience receives your presentation.
BTW, many audiences ask the speaker for a copy of their slides. A common response is to export to PDF and supply that document. This is not only easy on all concerned but it does protect much of the hard work it took to produce the presentation. Still, there are apps such as PDF to Keynote that will create a Keynote file containing the slide images (only).
Eve in the F2F environment, one can use an iPhone to record what is seen and said. There is even a periscope-like device that allows covert recording while holding the phone level.