I didn't see a way to do what you're asking, supported or unsupported. The runtime engine doesn't seem to recognize a file with EAR enabled, and it needs to be able to ask for the password to open it.
There's quite a few features not available in runtimes, so it's not too suprising. You could fall back to strategies used pre-fileamker 13, if it's required. One example might be to make an encrypted disk image and put the files on there.
I understand there are many limitations, but this one I find a bit surprising. The problem with a disk image is if they copy the file out, it's no longer encrypted. We are handing out a bunch of these databases and the data must be kept secure. I don't quite get what Filemaker is saying when they say not "Officially" supported. That makes it sound like there's a way to do it some how.
First, FMI does very often use the term "Not officially supported", but it does not mean much more than it says. I don't think you can put any meaning into that phrase.
Why it is not supported in runtimes, is another question. I do not know the reason, but it could be a licensing issue. Just like the fact that runtimes can not save as pdf, as FMI has to pay license to Adobe for the number of licenses they sell.
So maybe they use a library, which has the same licensing policy and as FMI can not control runtimes or the number of copies, they are forced to disable that feature.
However, it is a quite relevant question, so I suggest that you ask the right people, which you know. And I would suggest that you encourage them to at least explain if the reason is licensing or if they have choosed not to allocate resources to incorporate into runtime libraries...
I have inquired with the "right people", but haven't heard anything. ;-)
So, I thought I would inquire with the FM public, as they often have found the "unofficial" route to solve some of these issues. lol.
The wording is quite odd.