Struggling to decrypt a CENC-encoded file with Bento4 tools
You are trying to decipher the file with the Key ID instead of the Key itself. "23 b6 70 1b e9 8b 4e ea 80 4e 9b 59 6c 59 37 a5" is the identifier of the key, not the key itself. Sure you will not decipher. It is in the file in order for the DRM system to retrieve the key (sending or searching the keyID for getting the Key itself in return). Try to use the key value to decipher. Your mp4encrypt command should have been used with an option like: --key 1::0000000000000000 as your IV size is 8