Solved DCF filesystem: is or not a fake the date impressed on the pictures ?

Good morning my Teacher ... and hello guys !!!

As you know the DCF filesystem is widely used in the cameras and several embedded device devoted to take pictures.

Please, can you tell me if the DCF filesystem stores marks that unequivocally identify if is or not a fake the date impressed on the pictures so to ascertain that it has not added with Photoshop (or other similar graphical tools) ?

If so, at which offset this information is stored in ?

PS. I've not yet studied this filesystem . I'll do it in a next future. So the question could be malformed.

Bye bye !!!
 
As you know the DCF filesystem is widely used ...
DCF is not a file system. The media (actual storage device) used in cameras etc. is typically formatted using a FAT file system. DCF is a standard about how the files and directories in the file system are to be named; it for example says that the actual images shall be in a "DCIM" directory, which then shall have files with names such as "IMG_1234.JPG".

Please, can you tell me if the DCF filesystem stores marks that unequivocally identify if is or not a fake the date impressed on the pictures so to ascertain that it has not added with Photoshop (or other similar graphical tools) ?
Some specification somewhere (could be DCF, could be Exif) says that cameras shall put identifying information into the image file itself, which is typically in jpeg format (also sometimes also in tiff or other formats). That information includes things like "this picture was taken by Canon camera model ABC serial number 12345, on Monday 4/30 at 11:15 in the morning, at GPS coordinates 17d18m19s north and 71d51m41s east", obviously in addition to the actual image pixels (encoded for example in jpeg or tiff format).

Where is that information stored? Look up the actual Exif standard, or read the source code for open source tools that can decode and print exif data (for example exifdump).

However, the question you pose of authenticating a picture file is much harder. Certainly, with enough spare time, anyone can edit (create or modify) an image, and given the published standard put exif data on there that claims that it was taken by a certain camera at a certain date and place. How do you know that they are not lying? This is where cryptographic authentication comes into place: The camera could have a secret (like a cryptographic key) which it uses to "sign" each image file, and then the correctness of the signature could be verified by a third party using the published public key of the camera. This is for example what protocols such as ssh use to allow for passwordless login for users who have been authenticated using their public key. To my knowledge, normal cameras don't do this. Meaning: No, you can not verify that the image really came from the camera.
 
These are the replies that like to me, explained and clear: yes or not.
ralph = the wizard of the computer science engineering !!!

Thanks thanks very much for your time !
 
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