[HN Gopher] DEDA - Tracking Dots Extraction, Decoding and Anonym...
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       DEDA - Tracking Dots Extraction, Decoding and Anonymisation Toolkit
        
       Author : pavel_lishin
       Score  : 82 points
       Date   : 2025-04-01 21:11 UTC (1 hours ago)
        
 (HTM) web link (github.com)
 (TXT) w3m dump (github.com)
        
       | VladVladikoff wrote:
       | For those who missed it, this is an interesting and related
       | topic: https://news.ycombinator.com/item?id=42880704
        
       | chaps wrote:
       | Had the experience of poking at tracking dots recently for
       | circumstances I won't share here.
       | 
       | Do y'allself a favor and get a blue LED flashlight and point it
       | at a color print. It's shocking how many are printed. It looks
       | like a spattering of sand across the entire page!
        
       | mschuster91 wrote:
       | This gonna be pretty important in the next years... people, if
       | you plan on printing protest flyers and pamphlets, either get
       | them done in a professional print shop (if you know someone you
       | can trust, that is), or at the very least buy the printer in
       | cash, never ever connect it to the Internet, and only connect it
       | via USB to a Linux computer - macOS and Windows both will install
       | printer drivers automatically that might phone back to the
       | mothership and link your printer ID to some sort of identifier.
        
         | decimalenough wrote:
         | Wouldn't it be way easier to just track the people handing out
         | the flyers?
        
           | Terr_ wrote:
           | That depends on whether:
           | 
           | 1. You're looking for a very specific person.
           | 
           | 2. You want to unconstitutionally punish somebody for free
           | speech, and you don't care who, you just want to cheaply find
           | a convenient victim.
           | 
           | In that respect, tracking-dots are an invitation to #2, since
           | they don't really need much in the way of human labor-hours
           | or focus.
        
       | banku_brougham wrote:
       | Do black and white laser printers produce tracking dots?
       | 
       | Also, what is the meaning of this tracking, must every corner of
       | our lives be tracked just on principle?
        
         | doctoboggan wrote:
         | It's my understanding that the secret service requested
         | (required?) that the printer manufacturers start adding the
         | dots once the printers got good enough to easily recreate paper
         | bills. Because they are primarily a tool for tracking
         | counterfeiters, they are not needed with black a white printers
         | and thus are not included.
        
       | noodlesUK wrote:
       | I'm really curious what proportion of printers can be decoded
       | with public tools. Are there any stats on which manufacturers
       | codes have been cracked?
        
         | IvyMike wrote:
         | The github references this document: Timo Richter, Stephan
         | Escher, Dagmar Schonfeld, and Thorsten Strufe. 2018. Forensic
         | Analysis and Anonymisation of Printed Documents. In Proceedings
         | of the 6th ACM Workshop on Information Hiding and Multimedia
         | Security (IH&MMSec '18). ACM, New York, NY, USA, 127-138.
         | 
         | There is a copy here:
         | https://ericbalawejder.com/assets/hexview/Forensic-Analysis-...
         | Table 1 (manufacturer, #of printers analyzed, dots found):
         | Brother 1 no        Canon 10 yes        Dell 4 yes       Epson
         | 8 somemodels        Hewlett-Packard 43 somemodels        IBM 1
         | yes       KonicaMinolta 21 somemodels       Kyocera 4 yes
         | Lanier 1 yes        Lexmark 6 somemodels        NRG 1 yes
         | Okidata 9 somemodels        Ricoh 6 yes        Samsung 5 no
         | Savin 1 yes        Tektronix 4 no        Unknown 1 yes
         | Xerox 15 somemodels
         | 
         | It sounds like they mostly understand the dot patterns wherever
         | they found them, with some caveats that are explained in the
         | paper.
        
       | twalkz wrote:
       | > My printer does not print tracking dots. Can I hide this fact?
       | 
       | > If there are really no tracking dots, you can either create
       | your own ones (deda_create_dots) or print the calibration page
       | (deda_anonmask_create -w) with another printer and use the mask
       | for your own printer
       | 
       | The thought of being able to "spoof" the tracking dots of another
       | printer has interesting implications for deniability. Though I
       | guess in this case you'd still need access to the original
       | printer to print the anonmask...
        
         | decimalenough wrote:
         | Per Wikipedia, the dots' "arrangement encodes the serial number
         | of the device, date and time of the printing", so all you
         | really need to spoof somebody else's printer is the serial
         | number. Which can likely these days even be accessed remotely
         | through printer settings.
        
           | CobrastanJorji wrote:
           | No need to examine the printer. Just find a sheet of paper
           | that printer printed, decode the dots, and then print your
           | super illegal whatever with their printer's dots and a
           | timestamp that makes sense for whatever you're framing them
           | for doing. Nobody's ever gonna believe "the dots were a lie."
           | They sound too much like fingerprints.
        
       | otaviogood wrote:
       | Me and my team used these yellow tracking dots to reconstruct
       | shredded documents for a DARPA shredder challenge over a decade
       | ago. You can see our program highlight the dots as we reconstruct
       | the shredded docs. https://www.youtube.com/watch?v=uzZDhyrjdVo
       | Thanks to that, we were able to win by a large margin. :)
        
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       (page generated 2025-04-01 23:00 UTC)