Can't open a windows 10 encrypted file transferred to another PC because of the .PFILE extension

Question

Objective: Using Windows 10 functionality, send an encrypted folder of files to a remote pc and allow the files to be decrypted for use on the remote pc.

(updated after initial post)

I have studied this for a bit and I'm not having success. I did this using a folder with 3 .pdf files for simplicity to confirm I understand the process - I don't. I followed these steps:

1) Right-clicked on folder > Properties > Advanced > checked 'Encrypt contents...' > 
  OK'd my way out when the encryption was complete
  The folder and file icons show a lock symbol on them and the filename and extension remained the same as before.
2) Exported the encryption certificate to a .pfx
3) Imported the exported .pfx from the previous step into the remote pc
4) Transferred the file to the remote PC using an SD card
  The filename now has another extension added to it: '.PFILE'
  I can't get past this step
  Also, when I go into Properties > Advanced on the folder or contained files, instead of seeing the 'Encrypt Contents...' checkbox checked, it is unchecked.

The .PFILE extension is part of the Microsoft Rights Management service. It is not present when the file is on the encrypting machine.

I confirmed that the encryption process is effective on the encrypting machine by signing into another account on the same pc; that account could not open encrypted files until I imported the .pfx certificate into that user account. Again to confirm, those files in the 2nd user account on the encrypting pc do not have the .PFILE extension. The .PFILE extension only shows up on the remote pc.

So the issue is I don't understand is why .PFILE shows up on the remote PC and what do I do about it?

Added after yet more testing: When I copy an encrypted folder from the encrypting pc to another pc on my network using the network connection, things work OK. I.E., the copied folder and its internal files show up on the other pc as encrypted in the manner I was looking for. However, this does not solve my problem exactly.

I would like to transfer these files to a PC that is not on my network. I don't seem to be able to copy the encrypted folder to an SD card, nor can I send the encrypted files in a transmission to the remote PC. I'm guessing 'that's just the way it is', so I don't know how to accomplish my objective as stated above.

Additional Results: I used BitLocker on my SD card and achieved a make-do solution for my need.

However, I would like to understand if it is possible and how it can be done to open encrypted files when the extension .PFILE has been appended to the file on a different computer, or am I misunderstanding a fundamental aspect of encryption?

Answer 1

PFILE extensions in this case are an artifact of windows 10 encryption - encrypted file system for sure, maybe bitlocker as well. It happens when you copy a Win10 encrypted file onto a file system that can't handle encryption (e.g., exFAT).

Those PFILEs can be opened on the original PC, and perhaps on another properly configured Win10 box (don't forget to install the same keys/certs on it).

Bun on systems prior to Win10, I don't have any confidence these PFILES can ever be opened.

How to solve? The two not-so-useful answers:

1. Don't try to store encrypted files on that FAT (or other "old" file system) disk.
2. Copy the EFS file onto a file system that does support EFS (e.g., NTFS).

I have yet to find out how it would be possible to open a PFILE on a non-Win10 box, even though my target machines have all the right keys to open standard EFS files on an NTFS file system. Documentation is virtually non-existent (like you expected anything else).