Tags: z3
Rating: 5.0
A fun custom virtual machine where we used z3 to reconstruct flags (and passwords).
Find the full writeup at: https://saarsec.rocks/2021/11/30/proctf-cells.html
Thank you for writeup ;)
1. In flag obfuscation code keyflow generates from password using simple binary operations. To make it harder you may try to make dependencies longer and more complex. When I added this z3 started to stuck.
2. Also I supposed that somebody would try to write harder cryptoalgorithm like RC4 or TEA
The idea of this vm appeared from ICFPC 2009 contest (Lisp-like vm)
