
Recent Posts
Recent Comments
Archives
Categories
Meta
Author Archives: incertia
Cheap Nullstellensatz
I was recently asked to prove a nonexhaustive set of cases for the weak Nullstellensatz, and the proof was so deceptively simple I decided to share it. The main theorem goes along the lines of this. Nullstellensatz: Let be an … Continue reading
Posted in Math
Leave a comment
ISL 2017 A1
Problem A1: Let and be positive integers such that If , prove that the polynomial has no positive roots. Solution A1: We appeal to a similar strategy that is used in IMO 20122. Write … Continue reading
Posted in Math
Leave a comment
IMO 2018 Day 2
Day 2 had a bunch of really nice problems with more advanced techniques required to solve them. Problem 6 is also hard and I will be writing it up at a later time. Problem 4: A site is any point … Continue reading
Posted in Math
Leave a comment
IMO 2018 Day 1
I have solved problems 1 and 2. I have not yet attempted problem 3 but I believe that it is beyond me, especially within a time frame of four and a half hours. Problem 1: Let be the circumcircle of … Continue reading
Posted in Math
Leave a comment
I finally released a thing
It’s a small tool to parse Unity3D TestResults files from testing in CI/CD environments, but it’s a tool nevertheless. You can find it at https://hackage.haskell.org/package/unitytestresultparser.
Posted in Programming, Software
Leave a comment
Revenge of the Finite Fields
A few days ago, I posted some proofs and a construction of finite fields. It turns out there are a lot more nice constructions and proofs and problems related to finite fields, so I’ll be sharing some of them here. … Continue reading
Posted in Math
Leave a comment
Finite Fields for Mortals
I’ve been studying a bunch of cryptography lately, and I thought it would be nice to present finite fields in some relatively easy to understand way that doesn’t require too much prior knowledge. All that is really needed here is … Continue reading
Posted in CTF, Math
Leave a comment
UIUCTF2017 – uiuctfsck
This was a brainfuck interpreter that let you print out some internal machine state. Notice that the interpreter does not like it if we have the string “machine” in our format string. We examine the machine object, and notice that … Continue reading
Posted in CTF
Leave a comment
UIUCTF2017 – OldTV
Not many people solved this despite the author and I believing that this should have been an easy challenge. We were given the following program: Initially, you should try to verify the signature and compute , and realize that it … Continue reading
Posted in CTF, Math
Leave a comment
Codegate 2017 Prequals – BabyPwn
This was a straightforward ROP challenge, which was made difficult on our side due to bandwidth issues. Interestingly enough, every time we tried to leak the stack cookie it started with a null byte. We have a read primitive (actually … Continue reading
Posted in CTF
Leave a comment