Json output

README.md

@@ -96,6 +96,8 @@ I will not show all twelve gates of the circuit, but here are the gates selectin
                     |
 ```
 
+This binary will also output the verifying key and proof in json format to `data/vk.json` and `data/proof.json`.
+
 ## Building and running
 
 ### Install dependencies

src/prime_under_16.cpp

@@ -2,6 +2,8 @@
 #include "libsnark/zk_proof_systems/ppzksnark/tbcs_ppzksnark/tbcs_ppzksnark.hpp"
 #include "libsnark/common/default_types/tbcs_ppzksnark_pp.hpp"
 
+#include "util.hpp"
+
 using namespace libsnark;
 using namespace std;
 
@@ -171,5 +173,10 @@ int main()
 
     printf("%s\n", verified ? "Proof accepted" : "Proof false");
 
+    const tbcs_ppzksnark_verification_key<default_tbcs_ppzksnark_pp> vk = keypair.vk;
+
+    vk_to_json<default_tbcs_ppzksnark_pp>(vk, "data/vk.json");
+    proof_to_json<default_tbcs_ppzksnark_pp>(proof, "data/proof.json");
+
     return 0;
 }

src/util.hpp

@@ -0,0 +1,70 @@
+#include <fstream>
+#include "libff/algebra/curves/public_params.hpp"
+
+using namespace libsnark;
+using namespace libff;
+using namespace std;
+
+template<typename ppT>
+void vk_to_json(tbcs_ppzksnark_verification_key<ppT> vk, string pathToFile)
+{
+  ofstream vk_data;
+  vk_data.open(pathToFile);
+
+  G2<ppT> tilde(vk.tilde_g2);
+  tilde.to_affine_coordinates();
+
+  G2<ppT> alpha_tilde(vk.alpha_tilde_g2);
+  alpha_tilde.to_affine_coordinates();
+
+  G2<ppT> Z(vk.Z_g2);
+  Z.to_affine_coordinates();
+
+  accumulation_vector<G1<ppT>> IC(vk.encoded_IC_query);
+  G1<ppT> IC_0(IC.first);
+  IC_0.to_affine_coordinates();
+
+
+  vk_data << "[[\"" << tilde.X.c1 << "\", \"" << tilde.X.c0 << "\"],[\"" << tilde.Y.c1 << "\", \"" << tilde.Y.c0 << "\"]]," << endl;
+  vk_data << "[[\"" << alpha_tilde.X.c1 << "\", \"" << alpha_tilde.X.c0 << "\"],[\"" << alpha_tilde.Y.c1 << "\", \"" << alpha_tilde.Y.c0 << "\"]]," << endl;
+  vk_data << "[[\"" << Z.X.c1 << "\", \"" << Z.X.c0 << "\"],[\"" << Z.Y.c1 << "\", \"" << Z.Y.c0 << "\"]]," << endl;
+  vk_data << "[[\"" << IC_0.X << "\", \"" << IC_0.Y << "\"]";
+
+
+  for(size_t i=0; i<IC.size(); i++) {
+    vk_data << "," << endl;
+    G1<ppT> IC_N(IC.rest[i]);
+    IC_N.to_affine_coordinates();
+    vk_data << "[\"" << IC_N.X << "\", \"" << IC_N.Y << "\"]";
+  }
+
+    vk_data << "]" << endl;
+
+  vk_data.close();
+}
+
+template<typename ppT>
+void proof_to_json(tbcs_ppzksnark_proof<ppT> proof, string pathToFile)
+{
+  ofstream proof_data;
+  proof_data.open(pathToFile);
+
+  G1<ppT> V_g1(proof.V_g1);
+  V_g1.to_affine_coordinates();
+
+  G1<ppT> alpha_V_g1(proof.alpha_V_g1);
+  alpha_V_g1.to_affine_coordinates();
+
+  G1<ppT> H_g1(proof.H_g1);
+  H_g1.to_affine_coordinates();
+
+  G2<ppT> V_g2(proof.V_g2);
+  V_g2.to_affine_coordinates();
+
+  proof_data << "[\"" << V_g1.X << "\", \"" << V_g1.Y << "\"]," << endl;
+  proof_data << "[\"" << alpha_V_g1.X << "\", \"" << alpha_V_g1.Y << "\"]," << endl;
+  proof_data << "[\"" << H_g1.X << "\", \"" << H_g1.Y << "\"]," << endl;
+  proof_data << "[[\"" << V_g2.X.c1 << "\", \"" << V_g2.X.c0 << "\"],[\"" << V_g2.Y.c1 << "\", \"" << V_g2.Y.c0 << "\"]]" << endl;
+
+  proof_data.close();
+}