In image forensics, the presence of 9d91003d4080b03d40742c819ea5228e in metadata can be a clue. Many online images are stripped of their original EXIF data, but ICC profiles often remain. Recognizing this as a uRGB profile helps investigators determine the image's origin, editing history, or authenticity. As discussed on the ExifTool Forum, comparing this data can help determine if two photos were taken with the same camera or processed with the same software.
Hashes are "one-way." You can get a hash from a file, but you cannot easily recreate the file just by looking at the hash. This makes them ideal for securing passwords or marking sensitive "exclusive" data without revealing the contents to the public. 9d91003d4080b03d40742c819ea5228e exclusive
Not all hashes are malicious. Some genuine uses include: As discussed on the ExifTool Forum, comparing this