Bitcoin private key qrcode scraper

Tegenlicht today had an episode about Bitcoin where they announced they were going to give away €100 in Bitcoin. They were going to put up a Bitcoin wallet private key as a QR-code on the screen.

It seemed to me like a fun project to try and grab that Bitcoin. I coded an app that takes a screenshot every couple seconds and then tries to detect all QR-codes in it. If any of the codes look like a private key, I then used the Blockcypher API to determine the balance and empty the account into my own wallet.

Unfortunately, the NPO stream was probably too slow and I was a couple moments too late. It still was a fun challenge to program though and I learnt a bit about how Bitcoin works.

The code is available on here on Github

Thom Wiggers
PhD candidate at Radboud University

My research interests include (post-quantum) cryptography and protocols