DragonX/dragonx
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases 2 Wiki Activity

zkSNARK: Enforce disclosure of input note nullifiers

Browse Source
This commit is contained in:
Sean Bowe
2016-05-04 18:25:54 -06:00
parent ca8d6c9347
commit 2a2f3fb80f
3 changed files with 48 additions and 3 deletions
Download Patch File Download Diff File Expand all files Collapse all files

26
src/zcash/circuit/note.tcc
View File

@@ -32,33 +32,48 @@ class input_note_gadget : public note_gadget<FieldT> {
public:
std::shared_ptr<digest_variable<FieldT>> a_sk;
std::shared_ptr<digest_variable<FieldT>> a_pk;
std::shared_ptr<digest_variable<FieldT>> rho;
std::shared_ptr<PRF_addr_a_pk_gadget<FieldT>> spend_authority;
std::shared_ptr<PRF_nf_gadget<FieldT>> expose_nullifiers;
input_note_gadget(
protoboard<FieldT>& pb,
pb_variable<FieldT>& ZERO
pb_variable<FieldT>& ZERO,
std::shared_ptr<digest_variable<FieldT>> nullifier
) : note_gadget<FieldT>(pb) {
a_sk.reset(new digest_variable<FieldT>(pb, 252, ""));
a_pk.reset(new digest_variable<FieldT>(pb, 256, ""));
rho.reset(new digest_variable<FieldT>(pb, 256, ""));
spend_authority.reset(new PRF_addr_a_pk_gadget<FieldT>(
pb,
ZERO,
a_sk->bits,
a_pk
));
expose_nullifiers.reset(new PRF_nf_gadget<FieldT>(
pb,
ZERO,
a_sk->bits,
rho->bits,
nullifier
));
}
void generate_r1cs_constraints() {
note_gadget<FieldT>::generate_r1cs_constraints();
a_sk->generate_r1cs_constraints();
rho->generate_r1cs_constraints();
// TODO: This constraint may not be necessary if SHA256
// already boolean constrains its outputs.
a_pk->generate_r1cs_constraints();
spend_authority->generate_r1cs_constraints();
expose_nullifiers->generate_r1cs_constraints();
}
void generate_r1cs_witness(const SpendingKey& key, const Note& note) {
@@ -78,5 +93,14 @@ public:
this->pb,
uint256_to_bool_vector(note.a_pk)
);
// Witness rho for the input note
rho->bits.fill_with_bits(
this->pb,
uint256_to_bool_vector(note.rho)
);
// Witness the nullifier for the input note
expose_nullifiers->generate_r1cs_witness();
}
};