When exporting to ePub, ID offers the option to "Include Embeddable Fonts." However, for some inexplicable reason, ID is encrpyting some but not all embeddable fonts even though the licence states that embeddable fonts can be embedded in electronic documents.
My document uses Georgia and Courier New. Both are Open Type and listed as embeddable. When exporting to ePub using CS5.5, Georgia is embedded as is but Courier New is embedded and encrypted. This results in a file called "encryption.xml" that hides in the META-INF folder. This encryption file does not cause the file to fail validation -- Sigil, FlightCrew and ePubCheck all passed the file -- but it can cause the ePub to be rejected by some retailers and apparently can wreak havoc in some older ereaders.
The result is that you have either to not embed any fonts (not an option in my book as I use Courier to mimic HTML code) or you have to first remove the encryption.xml file from the archive then edit the ePub to remove the encrypted font and replace it with an unencrypted one.
So question is, why does Adobe encrypt Courier New? And why Courier New but not Georgia?