Exiv2

The SR2 format uses the DNGPrivateData tag to reference a private IFD containing these tags. SR2 images are written by the Sony DSC-R1, but this information is also written to ARW images by other models.

This SR2 sub-directory contains various other sub-directories, some of which are encrypted.

Reference: http://www.sno.phy.queensu.ca/~phil/exiftool/TagNames/Sony.html