About

HSCTF 2020 Crypto - Extremely Complex Challenge

Extremely Complex Challenge We are given two points on an Elliptic Curve, its order and parameter b. Using these quantities, we can recover parameter a. y^2 = x^3 + ax + b (mod p) y^2 - x^3 - b = ax (mod p) If we have two points on curve, (x1, y1) and (x2, y2), we can get (y1^2 - x1^3) - (y2^2 - x2^3) = a(x1 - x2) (mod p) a = (x1 - x2)^-1...

Read more