NSUCRYPTO 2017

I and @quandoan, @bmtd played together and get 3rd place in NSUCRYPTO 2017 The problems are challenging, orgainzer support very well. And they have prizes for us. This is the 2nd time we won International Students' Olympiad in Cryptography, I guess next year will be a lot harder. Many strong…

CODEGATE CTF 2018 RedVelvet, BabyRSA, Miro

CODEGATE CTF doesn’t have such good crypto challenges, all crypto challenges are disappointed. Miro is suprisingly easy, BabyRSA copies idea from HXP CTF 2017, RedVelvet is the challenge I use Z3 to solve. RedVelvet The check is easy, each function need around 2-3 bytes to pass a check.…

TWCTF 2017 - BabyDLP, BabyRSA, 3Rev

I had sometime at the weekend to play this CTF. One of my favorites CTF, good crypto challenges. By some magic, I wrote writeup for TWCTF 2016 but it takes me never to publish it. I’m so lazy. BabyDLP # Python 3 from signal import alarm from Crypto.Util.…

[ASISCTF QUAL 2017] Crows knows

ASIS is my favorite CTF, and my solution is a roller coaster. Crows knows Let’s start with this exciting challenge: [+] Opening connection to 146.185.143.84 on port 13245: Done ************************************************************** | Welcome to the Crow Impossible Task, crow knows the flag!! | | Your mission is to find x, y…

[0CTF] One Time Pad by Z3

This challenge can be solved by two ways, mathematically or using SMT Solver Intially, I want to remind you that there is a blog post written carefully how to solve it in mathematical way. So please read it first. One Time Pad 1 Now let take a look at the…