I was surprised to see that the Hidden Files password is stored very obviously as HiddenFilesPassword.txt, and that the index of known files is plain text.
?:\Program Files (x86)\Steam\steamapps\common\SKYBOX VR Video Player\PersistentData\HiddenFilesPassword.txt and sqlite4unity.s3db.
I request a feature that each of these files be encrypted while stored on the hard drive using AES or comparable algorithms. SQLite already has the native ability to encrypt data.