Intro

For a while Blu-ray discs only used the protections that they were designed with: AACS (mandatory) and BD+ (optionally). Because they failed to do the job, studios started to look in other directions: some used audio watermark known as Cinavia, some used structural protection, much like the ones used for DVDs (eg. ARccOS, RipGuard, etc).
For Blu-ray, it was Sony DADC division that created the Screen Pass protection, which was adopted by Eagle Pictures (Italy), Summit Entertainment (USA/Canada) and others (see the table below).

How it works

Sony DADC Screen Pass is a Java based (BD-J) structural protection and it tries to determine if the disc that is played is original or it is a clone. In the later case, the user receives a black screen with a message (Protection card) saying that the original disc should be used, no ripping tools allowed, visit something.continuemovie.com etc. and playback is either stopped or affected (segments of the movie are swapped around, repeated or in wrong order).
Also the users that don’t use clone mode and backup Main Movie only (no Java running, no active protection) are having a problem with picking the right Title/playlist for some movies, because the disc is filled with fake playlists with the same runtime, but subtle differences.
When AACS, BD+, region code, etc. are removed, tools like DVDFab and DVDFab Passkey need to hide some files and modify others from the original disc. The protection looks exactly for such changes in structure, hence the name: structural protection. For some time, DVDFab tools had a per-movie approach, because they were few.

StealthyClone

It is time for a generic anti-protection that will make the cloned disc appear as if it was the original one, hiding the fact that it was unprotected.
DVDFab presents StealthyClone anti-protection the world’s first truly generic approach to deal with Sony DADC Screen Pass and other structural protections that may appear. This way, users that want to keep the original menus and artwork of the disc are not forced to give them up any more, because the protection is rendered useless.
When the protected disc is trying to find out if it’s original and is asking through Java means about various files and performs checks on them, StealthyClone is hooked in and answers well. This way, the protection cannot tell if it is a clone or not and will continue with the correct playback of the movie.

Correct Main Playlist

Not only the Full Disc (clone mode) users will be satisfied with that. DVDFab has now a new, better-than-ever, algorithm to select the correct playlist when in Main Movie mode from the hundreds of fake ones. All the playlists in gray are very much likely to be fake.

Note 1: the information in above table is by no means complete, they’re just examples.
Note 2: some studios had just one-movie test release with this protection.
Note 3: of all the discs released for same movie in a country, not all of them may have fake playlists.
Note 4: in teritories where the movie is not released by the above mentioned company, usually it’s safe to say that the Blu-ray does not have this protection.