FCSC 2021 - Trappy Skippy

Posted on 03 May 2021, 18:00 in WriteUps • Tagged with ctf, write-ups, crypto, symmetric, block cipher, trapdoor

Write-up of a crypto challenge during FCSC 2021 - Breaking a trapped block cipher with only 14 plaintext-ciphertext pairs


Continue reading

FCSC 2021 - SmeaLog

Posted on 03 May 2021, 18:00 in WriteUps • Tagged with ctf, write-ups, crypto, elliptic curve, discrete log, integer modulo prime-power

Write-up of a crypto challenge during FCSC 2021 - Discrete logarithm on an elliptic curve defined over integers modulo a prime-power


Continue reading

Ledger Donjon CTF 2020 - SMPC Signature

Posted on 21 Nov 2020, 18:30 in WriteUps • Tagged with ctf, write-ups, crypto, elliptic curve, lattice, smpc, secret sharing

Write-up of a crypto challenge during Ledger 2020 CTF - Lattice based attack on ECDSA signatures using known-prefix nonce


Continue reading

TokyoWesterns CTF 4th 2018: Crypto - Revolutional Secure Angou

Posted on 04 Sep 2018, 08:23 in WriteUps • Tagged with ctf, write-ups, TokyoWesternsCTF, RSA, crypto

RSA-base challenge with a flawed prime numbers generation


Continue reading

Google CTF 2018: Crypto - MITM

Posted on 01 Jul 2018, 10:00 in WriteUps • Tagged with ctf, write-ups, GoogleCTF, curve25519, mitm, crypto

Man-in-the-middle attack on Curve25519-based handshake


Continue reading