During the mid-aughts, there was at least one serious proposal that every person would have their own private record store, which they carried around (PDFs on a thumb drive). Part of NHIN shootout. Every one had a pretty good laugh.

Repeating myself here: one way to protect patient privacy is to issue everyone globally unique identifiers. Then use translucent database techniques to hide the important.

Currently, linking records across our heterogeneous systems, with all the data quality challenges, prevents data from being encrypted (in transit or at rest).