Backup restoration lacks automatic integrity verification and user confirmation for unsaved changes

Problem

Emacs creates backup files with the ~file~ suffix and restores them via M-x revert-buffer. The current behavior overwrites the buffer without checking whether the backup file's contents match the original, and it provides no prompt when the buffer contains unsaved modifications.

Goal

Define how Emacs should automatically verify backup file integrity before reverting and how it should handle unsaved changes during restoration.

Questions

How can Emacs be designed to automatically verify backup file checksums before performing a revert?
What user-interface feedback or confirmation mechanism should be presented when restoring a backup that contains unsaved changes?