Tags: crypto reversing 

Rating: 5.0

Short form (link for full writeup):

* Yao's Garbled Circuit is used. It is not regenerated between multiple inputs.
* Dump garbled tables with a debugger.
* Obtain input keys for each bit for value 0 and 1.
* Parse the supplied verilog file and set inputs to each gate such that the circuit outputs true.

Original writeup (https://upbhack.de/posts/defcon-ctf-qualifier-2018-writeup-smcauth/).
kdrMay 15, 2018, 9:28 p.m.

A very nice challenge and a great writeup!