Write-up by @doegox and @PapaZours of Quarklabs.
Many thanks to you for the job and GG for solving the first 5 levels !
They did not solved this INSANE level witch is more dedicated to be solved after the CTF, due to the complexity of the task. But they correctly guess it was a fault injection (in fact it's more a race condition during the boot of the MCU).

Level6: [http://wiki.yobi.be/wiki/GreHack_2018_Writeups#Secret_Keeper_level_6_.28501_points.29](http://wiki.yobi.be/wiki/GreHack_2018_Writeups#Secret_Keeper_level_6_.28501_points.29)