This is the solution of the first LiveCTF Challenge “shiny-shells” of DEF CON CTF Qualifiers. A Paillier cryptosystem allowing, thanks to multiplicative homomorphic multiplication, to change the executed command.

This is the solution of the challenge “winter” from Dice CTF. Winternitz signature allowing to forge a signature from a previous valid signature.

This is the solution of the challenge “Chaos Theory” from ZK Hack IV . Thanks to pairing bilinearity, it was possibile to identify a message encrypted with a variant of ElGamal encryption over bls12-381 curves.

This is the solution of the challenge “Supervillain” from ZK Hack IV . It was possible to forge a Proof of Possession of a private key used in BLS signature thanks to the linearity of the scheme.

This is the solution of the challenge “Gamma Ray” from ZK Hack IV . It was possible to forge a nullifier of a circuit using the negation of a valid nullifier on a Miyaji-Nakabayashi-Takano curve.

This is the solution of the challenge “Upside-down Cake” from Potluck CTF. It was an modular equation solved after transformation by the Coppersmith method applied to bivariate polynomials.