I know that NTFS supports encryption but otherwise is closed source. Likewise, I am aware of add-ins such as truecrypt but I am interested in encryption being built-in vs being bolted on.
Windows – Are there any open source filesystems for Windows that support encryption
ext3filesystemsnfswindows
Best Solution
Keep in mind that encryption is often not done at the filesystem level. It's done at the block level, where sectors are actually read/written to disk. This allows one to use any filesystem with the encryption, as the filesystem sits on top of the encryption layer.