Black Hat Card Deck CTF

This post recounts Orange Cyberdefense’s Black Hat 2023 in-class CTF hidden within a custom playing-card deck, detailing a two-step crypto challenge: first, a Vigenère-decoded URL using the phrase WE HACK WE TRAIN YOU PWN, and second, an RSA task where participants factor the public modulus (e.g., via sympy) to rebuild the private key and decrypt the final message; it also notes participant engagement and provides a code repository for RSA key generation and reconstruction.