KB wrote:Yes, Katherine and popcornflix have hit the nail on the head. We do get frequent requests to password-protect Scrivener projects, but it's not like password-protecting a single file such as a Word document, which can be encrypted. As Katherine and popcornflix point out, a Scrivener project is not a single file but a folder full of many files. That entire directory would need encrypting, and it would need decrypting on read. That is far from simple. Would each file be decrypted as it was needed? Or would an entire (possibly huge) project directory be encrypted and have to be decrypted as a whole on project open?
This may be worth some more research, as I think this could be easier than you surmise. Pages has the same multi-file package structure as Scrivener and provides transparent encryption by simply packaging as an encrypted ZIP archive.
Files in an encrypted ZIP archive can be listed without the need to decrypt every file, so there is no barrier to Scrivener's existing functionality. Scrivener can ask for the password to an encrypted project upon open, then decrypt individual documents on the fly as they are accessed, fitting with its existing memory management model.
A quick search on Apple's developer site reveals an example app for browsing ZIP archives without unarchiving: https://developer.apple.com/library/content/samplecode/ZipBrowser/Introduction/Intro.html
Basically if Scrivener reads its folder structure as a ZIP archive you get encryption for free, and smaller disk footprint. This may also solve your issues with iCloud sync.