DEDA – Tracking Dots Extraction, Decoding and Anonymisation Toolkit

github.com

83 points·adulau··7 comments

I wouldn't be surprised if there are inkjet printers printing spy dots as well. I have an Epson Artisan 725 and I've noticed that it uses far more yellow ink than it ought to, given that the vast majority of my printing is black-and-white.

I'll have to do some testing to see for sure, though.

Earlier discussion of this and more sophisticated printer tracking codes:

https://news.ycombinator.com/item?id=14501894

Is it possible to avoid printing these dots in the first place?

That is covered in the README.

[0] https://github.com/dfd-tud/deda#5-anonymise-a-document-for-p...

In this case, the dots are still getting printed. The process described by the README involves masking out the printed metadata. This probably involves printing over or around it in a way that either destroys, corrupts or anonymises the information. This depends on the printer allowing you to print similar data on the same physical location as its dots, so it's possible that future printers will not have this vulnerability.

I was hoping there'd be some kind of custom firmware for printers that let me turn off this dot printing "feature" altogether.

> some kind of custom firmware for printers

Unfortunately, to the extend of my knowledge and google-fu, such a thing does not (currently) exist.

Funny thing is, non-free printer firmware was what first got Richard Stallman thinking about free software. Then came Symbolics and the rest is history. I wonder what it'd take to reverse engineer a printer?

Reply on news.ycombinator.com