[How] can I access from my MBP a shared file residing on WIndows XP encrypted via EFS?
I mounted the volume on the Mac using the WIndows user name and password, so I'm somehow imagining that gives the same authority as seeing the file on Windows. And that the decryption will occur on the Windows machine, with the data transmitted to the Mac in the clear.
From the Mac, I can see the file info (which EFS doesn't affect), but trying to open it gives "The operation cannot be completed because you do not have sufficient privileges for some of the items." (I think things are mounted properly as I can open the file if I go over to Windows and decrypt it first.)