Blu-ray Content Hash Verifier
Content hash verifier is used to verify the integrity of Blu-ray M2TS files. It has two versions:
- GUI version: right-click ‘Content Hash Verifier’ in Xreveal tray menu.
- Portable command line version
Feature
- Verify content hash of a ISO file
- Verify content hash of a folder
- Verify content hash of a drive
- The GUI version of Content Hash Verifier can verify the content hash of decrypted .m2ts files
Xreveal will attempt to restore AACS protection and CCI protection before verifying the content hash - The GUI version supports drag-and-drop files
- If the Content Hash cannot be verified, the m2ts sync byte (0x47) will be checked
Principle
The content hash is a an 8-byte hash value of a 192 KB M2TS data block. For regular BD, the content hash is the lower 8 bytes of SHA1(M2TS_BLOCK); for 4K UHD is the lower 8 bytes of SHA256(M2TS_BLOCK).
The content hash in a Blu-ray is stored separately for each layer in /AACS/ContentHash000.tbl, /AACS/ContentHash001.tbl, /AACS/ContentHash002.tbl...
- Content hashes are generated only for .m2ts files that are greater than or equal to 1344 KB.
- If the last data block is not exactly 196 KB, this block will be omitted to create a content hash.
- The M2TS data involved in the calculation is the actual data stored on the disc.
Because bus encryption is a software encryption set by the optical drive firmware, if bus encryption exists, it needs to be removed before calculating the hash value.