Deck of Cards CTF

The post describes the design and solution path of a crypto CTF hidden in a hacking-themed deck of cards for Black Hat, starting from a binary-encoded link leading to a Vigenère-ciphered URL (keyed with “WE HACK WE TRAIN YOU PWN”), followed by base64 data encrypted with RSA using intentionally weak primes. By factoring the provided RSA modulus (via SymPy), deriving the private key, and decrypting the ciphertext, solvers recover the final text (“cryptNinja”), with the article offering brief explanations of RSA key generation and the tools used.