Writeup for Asemoon from CryptoCTF 2025: breaking a custom CRC-style construction over GF(2) to recover a 64-bit secret key.
Writeup for Snails from CryptoCTF 2025: recovering an ECDSA private key from biased short nonces with a lattice (LLL) attack.
Writeup for the ASIS Primes RSA challenge from CryptoCTF 2025: abusing attacker-chosen primes and a faulty public exponent (e ^ 1) to decrypt the flag.
Writeup for Ikkyu San from CryptoCTF 2025: solving a discrete logarithm on a specially constructed elliptic curve over a 256-bit prime field.
Writeup for Lowdown from CryptoCTF 2025: forging signatures in a custom scheme by solving a discrete log over GF(256) matrix groups.
Writeup for Mechanic II from CryptoCTF 2025: exploiting an ML-KEM-1024 (Kyber) decapsulation oracle to recover the shared secret.
Writeup for Mitram from CryptoCTF 2025: recovering the flag from an oil-and-vinegar style multivariate map over GF(256).
Writeup for Phoney from CryptoCTF 2025: breaking a multi-prime RSA scheme using a leaked relation between the secret primes.
Writeup for Silky from CryptoCTF 2025: recovering a short secret vector from a noisy LWE-style oracle using lattice reduction (LLL).
Writeup for Sobata from CryptoCTF 2025: exploiting the special structure of an elliptic curve built from cube roots modulo p to solve a discrete log.
Writeup for Toffee from CryptoCTF 2025: forging a custom elliptic-curve signature by exploiting reused secret nonces.
Writeup for Interpol from CryptoCTF 2025: recovering the flag from a Lagrange interpolation oracle that leaks characters through rational data points.
