Cousin Wu Ka Lok

Second-year PhD student in the Computer Science Department at Stony Brook University. CTF, Maths enthusiast. A member of the Black Bauhinia (blackb6a) CTF team based in Hong Kong.

Blog

Fundamental Concepts Underlying Elliptic Curves (Level 2): Divisors and Pairings

11 May, 2022 56 minute read ★★★☆☆

Elliptic curve has a lot of nice structures attached to it. One of them is the idea of divisors. Using divisors, we can construct an example of a pairing, wh...

Fundamental Concepts Underlying Elliptic Curves (Level 1): Projective Coordinates

15 December, 2021 85 minute read ★★★☆☆

Last time we mentioned the basic concepts of Elliptic curves. However, there were some lingering questions about the weird representation of points in sage b...

Fundamental Concepts Underlying Elliptic Curves (Level 0): High-level Overview

11 December, 2021 39 minute read ★★☆☆☆

Elliptic Curve is one of the biggest topic in mathematics, for example number theory and geometry, and is used to, for example, prove the famous Fermat’s Las...

Coppersmith’s Method (Part II): Choosing the Right Lattice (1)

29 November, 2021 59 minute read ★★★☆☆

This time we will be proving the Coppersmith’s theorem using the proof method of Howgrave-Graham. We will use lattices and the lattice basis reduction algori...

Zetta-CTF: 🥥

19 November, 2021 38 minute read ★★☆☆☆

The following challenge is from the Zetta-CTF PHP: Horrific Puzzle, during the VXCON in Hong Kong, 27 Apr - 28 Apr 2019. The challenge is named 🥥. btw no one...