PKG

PKG is an archive format used to store digital versions of games on the Playstation Network. PKG files for PS3 games are not encrypted, but they are on the PS4 and Vita. There is currently no way to unencrypt them. Several Persona games use the PKG format, such as Persona 4: Dancing All Night, Persona 4 Golden, Persona 4 Arena 1 and 2, and Persona 5. Only the PS3 version of Persona 5 is unencrypted at the moment, and therefore possible to mod and datamine.

There are several methods to dump PSVita games by mounting the game while the system decrypts it as a way around the PKG encryption.

PKGView
| PKGView can extract all the files in a decrypted PKG. Just open the downloaded PKG file, right click the topmost directory and extract to source folder.