Tags: qr qrcode 

Rating: 5.0

Disclaimer: solved the challenge after the CTF ended. However, it was a nice dive into the QR rabbit hole.

TLDR: The bits are scrambled into a reading order (Left->Right, Top->Bottom). Assemble the bits and rearrange them according to QR standard. Also, the 15bits of format, mask and error correction are missing. Brute-force them to find one combination that works. Scan the resulting QR code for the flag.

https://meashiri.github.io/ctf-writeups/posts/202308-sekaictf/#qr-god

Original writeup (https://meashiri.github.io/ctf-writeups/posts/202308-sekaictf/#qr-god).