Your Apple iPhone running on iOS 14 does support encrypted drives but only those formatted using Apple File System (APFS)
Apple fanbois went gaga over Apple’s announcement at the WWDC that its latest iOS 14 operating system for iPhones will support encrypted drives. Apple had announced that iOS 14 powered devices could be connected to encrypted drives and read/write on them. At that time many thought that the iOS would allow any plug and play external encrypted devices could be connected to the iPhones and data could be accessed with a password.
It is not so. Apple has made good of its promise of letting iOS 14 users access encrypted drives through the Files app. This feature is already present in the first beta version of iOS 14 and iPadOS 14 available to developers and would be released in the final version for all iPhone and iPad users. Once the feature is available, you just have to connect the encrypted drive to the iOS 14 device, with the drive to show up in the sidebar of the Files app. You’re prompted to enter the password to read the encrypted data and access it. However, there is a catch!
The encrypted drive needs to be formatted in the proprietory Apple File System (APFS) format. Yessiree, you can’t access encrypted files in formats other than APFS format on your iPhone or iPad running on iOS 14.
With the beta version of iOS 14 already having encrypted drive support with APFS feature, it is not possible that that final release of iOS 14 will support all types of file formats and you are stuck with APFS.
APFS, or “Apple File System,” is an Apple alternative file system to the FAT, NTFS and FAT32 file systems for Windows. It was first introduced in macOS High Sierra. It’s optimized for solid-state drives (SSDs) and other all-flash storage devices, though it will also work on mechanical and hybrid drives. The APFS is fast and copying and pasting a folder is basically instantaneous, because the file system basically points to the same data twice. The only issue with the APFS file system is cross-platform compatability. It can’t even be used in older Apple macOS systems leave alone Linux and Windows 10 PC/laptops