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CovidPass: Making it badass by drawing inside the QR code

10 pointsby hrvachalmost 4 years ago
As a small, useless but fun hobby project, I wanted to try and draw something inside my EU Covid Pass QR certificate WITHOUT relying on error correction or rendering the digital certificate invalid.<p>TL;DR - some deflate misuse, mixed-mode alphanumeric and numeric QR encoding, mask choice override, padding the code with content that base45 encodes to numbers only and choosing them in a way to produce a meaningful image. Apparently, verifier apps are fine with it - every one I tried scans green.<p>This is a non-prod demo cert used for illustration of the concept with some funny images inside:<p>https:&#x2F;&#x2F;i.imgur.com&#x2F;3JonSRX.png<p>Would there be any interest in me doing a post explaining how it was done?<p>Also, what else should I draw inside?

5 comments

bellyfullofbacalmost 4 years ago
Neat. How about a pixel art that reads &quot;Legit certificate of vaccination&quot; in bad hand writing (like this[1]), but actually scans to a valid certificate?<p>TBH I didn&#x27;t even notice the skull and syringe at first glance, just a QR code.<p>[1] <a href="https:&#x2F;&#x2F;papersplease.fandom.com&#x2F;wiki&#x2F;Jorji_Costava?file=Fake_passport_1160.png" rel="nofollow">https:&#x2F;&#x2F;papersplease.fandom.com&#x2F;wiki&#x2F;Jorji_Costava?file=Fake...</a> vs legitimate passports in the game: <a href="https:&#x2F;&#x2F;steamtradingcards.fandom.com&#x2F;wiki&#x2F;Papers,_Please_-_Passports?file=Papers_Please_Artwork_7.jpg" rel="nofollow">https:&#x2F;&#x2F;steamtradingcards.fandom.com&#x2F;wiki&#x2F;Papers,_Please_-_P...</a>
hrvachalmost 4 years ago
Url link: <a href="https:&#x2F;&#x2F;i.imgur.com&#x2F;3JonSRX.png" rel="nofollow">https:&#x2F;&#x2F;i.imgur.com&#x2F;3JonSRX.png</a>
muzanialmost 4 years ago
I love it. I probably wouldn&#x27;t do it, but it&#x27;s interesting, especially for those of us who have been doing QR code apps for years.
JoshMandelalmost 4 years ago
What a delight! For sure would love to read the details.
severinealmost 4 years ago
Definitely interested in a writeup!