When you create a Microsoft Word file, you may think that all the information you’re giving is what you type into it and keep in the final version. If you’re seriously concerned about confidentiality, you can’t count on that. A file’s metadata can include information about its source and history which you never realized was there. Redaction may not remove all the information it’s supposed to chop out.
When you or somebody else installed Word on your computer, you were asked to enter information about yourself. It gets put into every file you create. If multiple people edit a document, the information on all of them gets into the metadata. Most people don’t mind, but in some cases it could be revealing too much information. If you entered gibberish or silly comments, they go into your documents.
Canvas fingerprinting in Web pages
The array of sneaky tricks to get past Internet users’ veil of privacy is astonishing. At least it would be, if we weren’t all past the capacity for astonishment. One which has been around for years is Canvas fingerprinting. It lets servers narrow your profile down to a small number of clients. Combined with other measures, it can uniquely identify you.
How Canvas works
Canvas wasn’t designed to spy on you. It’s a way to draw graphics very efficiently in a browser. It supports animation and interaction. In order to get fast performance, it allows hardware acceleration and doesn’t mandate the exact set of pixels to be drawn. The server can then get those pixels back using getImageData() or toDataURL() in the Canvas API.
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