What you get is more than you see. Hidden data in pics.

Recently there was a thread on possible insecurities in posting slab pics with the label visible. However, you may be posting data about yourself with any picture you put online. The broad term for nonobvious data in pics is metadata (also called embedded data). There are a few standard ways of embedding data which your camera device or computer might be adding. By adjusting settings, you can prevent this. Many image viewing and editing programs can detect and remove metadata added in a standard way. I’ve suggested to Peter (owner of cointalk) that images on cointalk be routinely scanned and standard metadata be removed.

However, there are many nonstandard ways to add metadata. Sometimes this is done deliberately as a means to identify ownership of the image. Companies that own lots of images that are online routinely use proprietary metadata and scan-bots to find other companies or individuals who may be using the images without permission. A more nefarious use is by hackers to gather information on individuals regarding their personal info and valuable things (jewelry, coins, art, guns, etc.) they might own. If your camera device or computer is hacked, then malware that adds nonstandard metadata to all images can be installed. The metadata can then be used to track any images you post online back to you.

The image below has four messages about coins embedded in it. Feel free to download it and try to find the messages. Two are easy to find, one is medium, fourth is hard. If you find any, please post.

Cal

 

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The digital world is not my forte by a longshot. I am the guy that people come to when they have car problems. Not digital problems. But your post intrigued and concerned me a bit. I have been known to pull photos off the web and bring them here to ask questions about. If I am reading your post properly, someone may have a photo protected and perhaps not appreciate that I posted his photo and possibly track it back to me..... Now I did download and perused all these unfamiliar windows on your photo. Are the messages below what you are talking about?

 

Well that sucks. Facebook used to contain GPS hidden data in photos where anyone with knowledge would be able to determine where a photo was taken. It was known to pinpoint where a fishing or hunting location photo was taken. Technology has just gotten too invasive.

 

My tools and I are very rusty. I had to do all sorts of metadata-related stuff with image files in a previous life, but I find to my consternation that I don't even have ImageJ or ImageMagick installed on my current machine.

I was able to find the comment attached to the file (...round...), and another message by dumping strings from it (...history...). If you've embedded something as a watermark or some other non-text format, I probably won't spot it.

 

On the other hand, some pro-level cameras now use metadata to cryptographically sign images, making it possible to prove that they haven't been manipulated with post-processing. That's becoming increasingly relevant as AI tools ramp up. (I hope we don't reach a point where AI tools can convincingly edit images and then rewrite signatures.)

 

I found "...round." as well. I found a thumbnail pic of the entire slab too!

 

Finding “round” and “history” by dictionary search of the file is a good start. “round” is in a jpg comment which has the complete sentence. Many pic viewers can show jpg comments. For example, in irfanview, click on image, then information, then Comment*. In faststone, click on view, then image properties, then JPEG comment. I’ll let someone post the entire message.

“history” is in a text file slapped on the end of the jpg file. Easiest way to see the whole message is first, change the file extension from .jpg to .txt. Then open it with a simple text editor, like Notepad. Go to the end and read the whole sentence. Please post.

Cal

 

Very surprised there is an embedded thumbnail of the whole slab. Good work! How did you find it? If the cert. no. is readable, please PM it to me for verification. If the cert. no. is not readable, please post the thumbnail here. Cal

 

I opened the file in Photoscape X and hit Ctrl+I (show info). There is a small version of the slab thumbnail shown in the pop-up info box. I'll show a screenshot...can't seem to zoom in enough to read info on label, but I assume some other software would allow the thumbnail to be viewed. Dunno. Gonna go get some gin now...good luck.

 

Corgi,

Thanks for finding this. Look's like a serious breach of security on the part of the image editing software I use. Folks crop images for many reasons. One of the reasons is to eliminate confidential data. That gets defeated if the cropped image file contains an image of the original pic. I'm going to install Photoscape and investigate further.

BTW, you also discovered the jpg comment: "Most coins are round." Congrats!

Cal

 

Wow you're paranoid! The cert# is readable and checks out on NGC. All I did was edit in Picasa and show properties. The thumbnail is supposedly 512x384 pixels but doesn't display that size in Picasa. I imagine there's better software to extract it full size. My images and seller images I've saved don't have much in the way of metadata. I have no idea how you got the thumbnail of the full slab into your cropped image.

What you really don't want is your GPS coordinates embedded in your photos. I tried it on my iPhone and it seems like you have to go out of your way to do that though.

What you should do instead on an iPhone is adjust the location in the image to the address of your local police station or crack house.

 

Forum members are doing great at finding the messages in the image and its file. I'm impressed. Coincorgi found one. JeffB discovered one more (he PM'd me) and is about to discover another. The easiest one stares you in the face; no need to explore the file structure.

Cal

 

Maybe I'm paranoid; maybe just like to explore image file structures. I am paranoid about secure backups though: offsite and air-gapped. I do know of cases of folks being robbed, even killed, because of their coin collection ... ask Willis Dupont.

I'm not too concerned about the cert. no. of that coin being known. I bought it via Teletrade decades ago and never showed the coin anywhere but here. Some older folks may remember Teletrade from pre-internet days; you bid over the phone. It later developed an internet site and then was swallowed by Stack's Bowers.

Cal

 

After doing some research, it turns out that some (all?) Android phones create a thumbnail that is embedded in .jpg images they create. This “feature” can be turned off with some manipulation but may be enabled again at the next OS upgrade. Editing the images will usually not remove the thumbnail. This may seem trivial if cropping out the label of a slab. But what if names on a legal document or secrets on a company document needed to be cropped out?

One thing that will remove the thumbnail is to convert a .jpg file to a .png file. This is desirable for editing anyway. Many folks don’t realize it, but if a .jpg is edited, the new file will usually be changed in ways other than the edit. This is due to the lossy compression algorithm used to create .jpg files. After successive edits, the entire image will have less resolution compared to the original. The downside of .png files is they are significantly larger than corresponding .jpg files.

Cal

 

I was about to post a GTG with one of my coins, but now I've got to do something with this jpg lol! Bummer!

 

My comprehension of this entire thread, from OP to each responding post, can be summed up in one GIF......

 

The last string in the file (using the Unix 'strings' command) is

That string of numbers -- if you look at it as pairs of numbers, they're all less than or equal to 26, which hints that they correspond to letters.

Just doing A = 1, B = 2, etc. doesn't produce anything that makes sense.

It's too short a string to do frequency analysis, so I'm expecting it's some constant offset. "Rot13" is a common rotation (add/subtract 13 from each), but that doesn't yield anything legible, either.

Since the lowest number is 8, let's see if subtracting 7 from each one does anything. Nope, that either.

At this point, I'd either keep trying other offsets, or write a program to try them all and list the results -- but I'm spending a bit too much time here. Maybe later.