minervas-stopwatch - TJCTF 2026 Ankith Abhayan 2026-06-11 Crypto tl;dr ECDSA signature samples with biased nonce of varying bit lengths given. Private key modeled as an instance of the Hidden Number Problem (HNP). Recovery with LLL. Read More Elliptic Curve TJCTF HNP Lattice ECDSA
Tabula Recta - InCTF Internationals 2021 ph03n1x 4l3x1 2021-08-20 Crypto / RC4 cipher / InCTFi Official writeup of Crypto challenge “Tabula Recta” from InCTFi 2021 tl;dr Retrive first few bytes of table through Matrix calculations, then find which special b-exact key is used. Read More Elliptic Curve RC4 Password Manager