I want to create a bit-by-bit backup of my DVD and a Blu-ray disc without removing its encryption. Is dd be the best method, and if so, what flags or settings should I use? Also, is comparing the SHA-256 hash of the generated ISO file with the hash of the original disc’s raw data (read from /dev/sr0) the best method for verifying the backup’s integrity?
ddrescue can do a really good job. But for blueray you’ll need a patched firmware.
i was going to extol dd_rescue’s virtues, but my own efforts to do what OP is trying to accomplish proves that they’ll have limited success thanks to drm.
libdvdcss handles DVDs, but like I mentioned, blueray drives need to be patched.