Question about decryption

[mmkvdza]

So I have been searching for a way to decrypt and backup my own Blu-rays for easier viewing under Linux and it seems makemkv can do the job nicely. But I am am not sure of its limitations.

The FAQ part of the official page says that "MakeMKV supports all commercial Blu-ray discs protected by latest versions of AACS and BD+" HERE, it also says that you can pass a volume key to MakeMKV HERE when decrypting from ISO or from copied files.

So why would I need a volume key? Does the key from the disc get lost in those two cases?

And how future safe is decryption directly from Blu-rays with makemkv? Will I need to find those keys to decrypt my future Blu-rays?

Thanks!

[dcoke22]

As I understand it, for commercial blu-ray discs, MakeMKV can figure out everything it needs for decryption from the disc. For UHDs (4k blu-rays), the keys still need to be downloaded. By default, MakeMKV attempts to download keys when it needs to and saves the results for future use on your local filesystem.

As for passing a volume key when decrypting from an ISO or from plainly copied files… decrypting a blu-ray is a bit more convoluted that most people realize. viewtopic.php?f=8&t=22790&p=94197#p94197
Mike says:

MakeMKV rule is that the backup (encrypted or decrypted) is as good as original disc. However original disc contains more data than just files, and for this reason MakeMKV has to save this data somehow.
On non-decrypted backups MakeMKV creates a single file called discatt.dat where it saves all disc attributes.
On decrypted backups MakeMKV creates a MAKEMKV folder where it puts all data it either deleted from the disc (like AACS directory) or files that describe additional metadata destroyed during decryption.

Your question about decrypting blu-rays in the future is a good one, but it supposes that you'll be able correctly read your optical discs in the future. I don't know that you can assume that to be true as discs and drives degrade over time.
In any case, if you're willing to save the 'raw' .mkv files made by MakeMKV, the need to decrypt the disc again in the future should be limited, excepting catastrophic storage failure. If you for some reason want to decrypt the disc again in the future, and assuming you can correctly read the disc, then MakeMKV should continue to be able to decrypt it assuming you have a working copy of MakeMKV installed.

[ham6817]

Put the disk/iso into make MKV and let it do its job/ done

[mmkvdza]

For UHDs (4k blu-rays), the keys still need to be downloaded. Be default, MakeMKV attempts to download keys when it needs to and saves the results for future use on your local filesystem.

That sounds good to me, I prefer to buy series as blu-ray and view them directly with my media devices without the discs and in Linux the encryption is very anyoing and doesn't let you play half of the things you buy. let's hope the next big series will have known keys.

Regards

[thetoad]

makemkv isn't a perfect tool if your goal is to make "playable" backups (i.e. menus and all). it doesn't do anything to remove region coding (easy enough to do manually if not in java) or any java manipulations to fix java based protections. It's really just designed to take a dvd/bluray and turn it into mkvs. that's it.