Checking against a known good hash value successfully probably means that an image file is not altered, but you don’t always have the hash. Do the various image formats (ISO, BIN/CUE, MDF/MDS, etc.) include any error detection or integrity check mechanism in the files themselves (if I remember correctly, RAR, for example, stores CRC32 and error recovery data)? For me, mount-it-with-Daemon-Tools-and-see-if-it-works type of checking doesn’t seem too reliable. If I changed a couple of bytes in some sensitive place of an image, what are my chances of finding the error? Daemon Tools or any other virtual drive software would probably mount the image just fine, I guess.