pedersen-libsnark/pedersen.cpp

#include <stdlib.h>
#include <iostream>
#include <fstream>

#include "libff/algebra/fields/field_utils.hpp"
#include "libsnark/zk_proof_systems/ppzksnark/r1cs_ppzksnark/r1cs_ppzksnark.hpp"
#include "libsnark/common/default_types/r1cs_ppzksnark_pp.hpp"
#include "libsnark/gadgetlib1/pb_variable.hpp"

#include "ecgadget.hpp"

using namespace libsnark;
using namespace std;

int main()
{
  // Initialize the curve parameters

  default_r1cs_ppzksnark_pp::init_public_params();

  typedef libff::Fr<default_r1cs_ppzksnark_pp> FieldT;
  
  // Create protoboard

  libff::start_profiling();

  cout << "Keypair" << endl;

  protoboard<FieldT> pb;
  pb_variable<FieldT> outx, outy;
  pb_variable<FieldT> a, b;

  // Allocate variables

  outx.allocate(pb, "outx");
  outy.allocate(pb, "outy");
  a.allocate(pb, "a");
  b.allocate(pb, "b");

  // This sets up the protoboard variables so that the first n of them
  // represent the public input and the rest is private input

  pb.set_input_sizes(2);

  // Initialize gadget

  ec_pedersen_gadget<FieldT> ped(pb, outx, outy, a, b);
  ped.generate_r1cs_constraints();
  
  const r1cs_constraint_system<FieldT> constraint_system = pb.get_constraint_system();

  const r1cs_ppzksnark_keypair<default_r1cs_ppzksnark_pp> keypair = r1cs_ppzksnark_generator<default_r1cs_ppzksnark_pp>(constraint_system);

  // Add witness values

  cout << "Prover" << endl;
  
  pb.val(a) = FieldT::random_element();
  pb.val(b) = FieldT::random_element();
  cout << "Computing " << pb.val(a) << "*G + " << pb.val(b) << "*H" << endl;

  ped.generate_r1cs_witness();

  const r1cs_ppzksnark_proof<default_r1cs_ppzksnark_pp> proof = r1cs_ppzksnark_prover<default_r1cs_ppzksnark_pp>(keypair.pk, pb.primary_input(), pb.auxiliary_input());

  cout << "Verifier" << endl;

  bool verified = r1cs_ppzksnark_verifier_strong_IC<default_r1cs_ppzksnark_pp>(keypair.vk, pb.primary_input(), proof);

  cout << "Number of R1CS constraints: " << constraint_system.num_constraints() << endl;
  cout << "Primary (public) input: " << pb.primary_input() << endl;
  cout << "Auxiliary (private) input: " << pb.auxiliary_input() << endl;
  cout << "Verification status: " << verified << endl;

  ofstream pkfile("pk_pedersen");
  pkfile << keypair.pk;
  pkfile.close();
  ofstream vkfile("vk_pedersen");
  vkfile << keypair.vk;
  vkfile.close();
  ofstream pffile("proof_pedersen");
  pffile << proof;
  pffile.close();

  return 0;
}