3 ms·
Hidden image data in photos that I know about: (1) Exif meta-data (Exchangeable image file format) which are things like resolution and dates, but can include
by alister 14y ago
Hidden image data in photos that I know about:
(1) Exif meta-data (Exchangeable image file format) which are things like resolution and dates, but can include serial numbers as well. Here's a handy list of cameras (usually high-end ones) that betray your privacy by embedding a serial number:
http://www.stolencamerafinder.com/listmodels http://www.stolencamerafinder.com/listmodels
(2) IPTC meta-data (International Press Telecommunications Council), though I have yet to see a photo "in the wild" that uses it.
(3) XMP meta-data (Adobe Extensible Metadata Platform). This is added by Photoshop for example. It's two long numbers (DocumentID and InstanceID) which are different for each image.
(4) DRM and anti-counterfeiting stuff that might be added by image editing tools. (Many color copiers do this in the case of paper prints, for example.)
- alister 14y agoI want to add some tips: Exif is the one everyone knows, but don't discount #3 and #4 (i.e., identifiers added by image editing tools). To keep a photo untraceable: Delete the Exif data using a tool like IrfanView. To edit the photo, download a fresh copy of an open source editing program or a commercial editing tool that does not need registration or activation. After you're done working on the photo, delete the editing program. For a higher level of security (to guard against the possibility of a GUID or hostname from the OS being embedded in the image), do all of the above on a computer that is not traceable to you, or on a fresh install of the OS, which you wipe after you are finished.
- Luyt 14y agoAlso, seed the network card with a fresh random MAC on eevery reboot, or more often.
- jlarocco 14y ago"betray your privacy" is a pretty loaded way to say that.
- bigiain 14y agoSensor noise can also be used to identify pictures taken with a specific camera: http://wrap.warwick.ac.uk/3318/ http://wrap.warwick.ac.uk/3318/ If I were being truly paranoid, I'd use some steganography software to write random "data" across all the low-order bits of any images I _really_ didn't want traced back the the sensor in my camera/phone/videocamera...