What is Metadata and how can it hurt your Privacy?

Metadata is data that describes other data. An example of this would be the email header contained within each email you send. It contains identifying information about the sender, and how the receiver is to read the email. But metadata can be a serious hindrance to your online security. It comes in all forms, and in many instances, you have to really know what you are doing to circumvent it on your own. Say you send a picture to someone that you took of your dog on your iPhone over email. You chose to send this picture through ProtonMail to make sure that it was fully encrypted and your IP address was stripped from the header. One would assume that you are making use of good security and privacy tactics, right? But the truth is that you would be wrong.

As I said before, metadata comes in all shapes and sizes and is even located inside that picture of your dog. Your iPhone that was used to take said photo recorded a lot of information about the photograph and stored it along with the image. Things like the data and time it was taken, size of the image, device it was captured on, and even the location where the photo was taken can all be included inside what we call the EXIF data on the image. So simply sending an image to someone could have completely ruined the work you have done to remain anonymous. Privacy International has more talk about metadata that you check out at this link here: https://www.privacyinternational.org/node/53