Blue ray movies are encrypted to prevent unauthorized copying. Someone figured out and published the decryption key making copying possible. The movie companies went nuts and tried to suppress dissemination of the key, but it was out of the bag. That 09f9 number is the key that was formerly a big secret. Now that you know it, you can copy blue ray discs.
Any Blu-ray player has to know the key in order to play a disc. So they’d have to have some way to update every single player. There would be no feasible way to do that.
Blue ray movies are encrypted to prevent unauthorized copying. Someone figured out and published the decryption key making copying possible. The movie companies went nuts and tried to suppress dissemination of the key, but it was out of the bag. That 09f9 number is the key that was formerly a big secret. Now that you know it, you can copy blue ray discs.
Why didn’t they just change it? Set a new encryption key for every disc?
Any Blu-ray player has to know the key in order to play a disc. So they’d have to have some way to update every single player. There would be no feasible way to do that.
Can you imagine having to update your Blu-ray player each time a new movie came out?