I have been struggling to get embedded fonts to appear on Kindle Fire and Nook HD.In order to make them work, I had to replace the encrypted fonts in the .epub file with non-encrypted ones, and delete the encryption.xml file. Now they display correctly on both devices. I have used only Adobe fonts in this book, which Adobe tells me don't require additional licensing. Do I have a problem since the fonts are now not encrypted? And if so, is there another way to get encrypted fonts to work on Kindle and Nook.
Font embedding is a very confusing issue because it depends on the capabilities of the EPUB reader. I really haven't had the time to learn all the fine points.
I know that it now works correctly in InDesign CC if you're targeting iBooks, but I'm not sure it's guaranteed to work on other readers. With InDesign CS6, I believe you're using the correct workaround.
As per the guiddance from NookPress Support, embedded fonts should not be in encrypted form in EPUB. So you will have to use non-encrypted fonts for these devices. The only problem is somebody easily extracting the fonts and using them without license or permission.