ark-r1cs-std/crypto-primitives/src/nizk/gm17/constraints.rs
crypto-primitives/src/nizk/gm17/constraints.rsRaw
1use crate::nizk::{gm17::Gm17, NIZKVerifierGadget};
2use algebra::{AffineCurve, Field, PairingEngine, ToConstraintField};
3use r1cs_core::{ConstraintSynthesizer, ConstraintSystem, SynthesisError};
4use r1cs_std::prelude::*;
5
6use gm17::{Proof, VerifyingKey};
7use std::{borrow::Borrow, marker::PhantomData};
8
9#[derive(Derivative)]
10#[derivative(Clone(bound = "P::G1Gadget: Clone, P::G2Gadget: Clone"))]
11pub struct ProofGadget<
12 PairingE: PairingEngine,
13 ConstraintF: Field,
14 P: PairingGadget<PairingE, ConstraintF>,
15> {
16 pub a: P::G1Gadget,
17 pub b: P::G2Gadget,
18 pub c: P::G1Gadget,
19}
20
21#[derive(Derivative)]
22#[derivative(Clone(
23 bound = "P::G1Gadget: Clone, P::GTGadget: Clone, P::G1PreparedGadget: Clone, \
24 P::G2PreparedGadget: Clone, "
25))]
26pub struct VerifyingKeyGadget<
27 PairingE: PairingEngine,
28 ConstraintF: Field,
29 P: PairingGadget<PairingE, ConstraintF>,
30> {
31 pub h_g2: P::G2Gadget,
32 pub g_alpha_g1: P::G1Gadget,
33 pub h_beta_g2: P::G2Gadget,
34 pub g_gamma_g1: P::G1Gadget,
35 pub h_gamma_g2: P::G2Gadget,
36 pub query: Vec<P::G1Gadget>,
37}
38
39impl<PairingE: PairingEngine, ConstraintF: Field, P: PairingGadget<PairingE, ConstraintF>>
40 VerifyingKeyGadget<PairingE, ConstraintF, P>
41{
42 pub fn prepare<CS: ConstraintSystem<ConstraintF>>(
43 &self,
44 mut cs: CS,
45 ) -> Result<PreparedVerifyingKeyGadget<PairingE, ConstraintF, P>, SynthesisError> {
46 let mut cs = cs.ns(|| "Preparing verifying key");
47 let g_alpha_pc = P::prepare_g1(&mut cs.ns(|| "Prepare g_alpha_g1"), &self.g_alpha_g1)?;
48 let h_beta_pc = P::prepare_g2(&mut cs.ns(|| "Prepare h_beta_g2"), &self.h_beta_g2)?;
49 let g_gamma_pc = P::prepare_g1(&mut cs.ns(|| "Prepare g_gamma_pc"), &self.g_gamma_g1)?;
50 let h_gamma_pc = P::prepare_g2(&mut cs.ns(|| "Prepare h_gamma_pc"), &self.h_gamma_g2)?;
51 let h_pc = P::prepare_g2(&mut cs.ns(|| "Prepare h_pc"), &self.h_g2)?;
52 Ok(PreparedVerifyingKeyGadget {
53 g_alpha: self.g_alpha_g1.clone(),
54 h_beta: self.h_beta_g2.clone(),
55 g_alpha_pc,
56 h_beta_pc,
57 g_gamma_pc,
58 h_gamma_pc,
59 h_pc,
60 query: self.query.clone(),
61 })
62 }
63}
64
65#[derive(Derivative)]
66#[derivative(Clone(
67 bound = "P::G1Gadget: Clone, P::GTGadget: Clone, P::G1PreparedGadget: Clone, \
68 P::G2PreparedGadget: Clone, "
69))]
70pub struct PreparedVerifyingKeyGadget<
71 PairingE: PairingEngine,
72 ConstraintF: Field,
73 P: PairingGadget<PairingE, ConstraintF>,
74> {
75 pub g_alpha: P::G1Gadget,
76 pub h_beta: P::G2Gadget,
77 pub g_alpha_pc: P::G1PreparedGadget,
78 pub h_beta_pc: P::G2PreparedGadget,
79 pub g_gamma_pc: P::G1PreparedGadget,
80 pub h_gamma_pc: P::G2PreparedGadget,
81 pub h_pc: P::G2PreparedGadget,
82 pub query: Vec<P::G1Gadget>,
83}
84
85pub struct Gm17VerifierGadget<PairingE, ConstraintF, P>
86where
87 PairingE: PairingEngine,
88 ConstraintF: Field,
89 P: PairingGadget<PairingE, ConstraintF>,
90{
91 _pairing_engine: PhantomData<PairingE>,
92 _engine: PhantomData<ConstraintF>,
93 _pairing_gadget: PhantomData<P>,
94}
95
96impl<PairingE, ConstraintF, P, C, V> NIZKVerifierGadget<Gm17<PairingE, C, V>, ConstraintF>
97 for Gm17VerifierGadget<PairingE, ConstraintF, P>
98where
99 PairingE: PairingEngine,
100 ConstraintF: Field,
101 C: ConstraintSynthesizer<PairingE::Fr>,
102 V: ToConstraintField<PairingE::Fr>,
103 P: PairingGadget<PairingE, ConstraintF>,
104{
105 type VerificationKeyGadget = VerifyingKeyGadget<PairingE, ConstraintF, P>;
106 type ProofGadget = ProofGadget<PairingE, ConstraintF, P>;
107
108 fn check_verify<'a, CS, I, T>(
109 mut cs: CS,
110 vk: &Self::VerificationKeyGadget,
111 mut public_inputs: I,
112 proof: &Self::ProofGadget,
113 ) -> Result<(), SynthesisError>
114 where
115 CS: ConstraintSystem<ConstraintF>,
116 I: Iterator<Item = &'a T>,
117 T: 'a + ToBitsGadget<ConstraintF> + ?Sized,
118 {
119 let pvk = vk.prepare(&mut cs.ns(|| "Prepare vk"))?;
120 // e(A*G^{alpha}, B*H^{beta}) = e(G^{alpha}, H^{beta}) * e(G^{psi}, H^{gamma}) *
121 // e(C, H) where psi = \sum_{i=0}^l input_i pvk.query[i]
122
123 let g_psi = {
124 let mut cs = cs.ns(|| "Process input");
125 let mut g_psi = pvk.query[0].clone();
126 let mut input_len = 1;
127 for (i, (input, b)) in public_inputs
128 .by_ref()
129 .zip(pvk.query.iter().skip(1))
130 .enumerate()
131 {
132 let input_bits = input.to_bits(cs.ns(|| format!("Input {}", i)))?;
133 g_psi = b.mul_bits(cs.ns(|| format!("Mul {}", i)), &g_psi, input_bits.iter())?;
134 input_len += 1;
135 }
136 // Check that the input and the query in the verification are of the
137 // same length.
138 assert!(input_len == pvk.query.len() && public_inputs.next().is_none());
139 g_psi
140 };
141
142 let mut test1_a_g_alpha = proof.a.add(cs.ns(|| "A * G^{alpha}"), &pvk.g_alpha)?;
143 let test1_b_h_beta = proof.b.add(cs.ns(|| "B * H^{beta}"), &pvk.h_beta)?;
144
145 let test1_exp = {
146 test1_a_g_alpha = test1_a_g_alpha.negate(cs.ns(|| "neg 1"))?;
147 let test1_a_g_alpha_prep = P::prepare_g1(cs.ns(|| "First prep"), &test1_a_g_alpha)?;
148 let test1_b_h_beta_prep = P::prepare_g2(cs.ns(|| "Second prep"), &test1_b_h_beta)?;
149
150 let g_psi_prep = P::prepare_g1(cs.ns(|| "Third prep"), &g_psi)?;
151
152 let c_prep = P::prepare_g1(cs.ns(|| "Fourth prep"), &proof.c)?;
153
154 P::miller_loop(
155 cs.ns(|| "Miller loop 1"),
156 &[
157 test1_a_g_alpha_prep,
158 g_psi_prep,
159 c_prep,
160 pvk.g_alpha_pc.clone(),
161 ],
162 &[
163 test1_b_h_beta_prep,
164 pvk.h_gamma_pc.clone(),
165 pvk.h_pc.clone(),
166 pvk.h_beta_pc.clone(),
167 ],
168 )?
169 };
170
171 let test1 = P::final_exponentiation(cs.ns(|| "Final Exp 1"), &test1_exp).unwrap();
172
173 // e(A, H^{gamma}) = e(G^{gamma}, B)
174 let test2_exp = {
175 let a_prep = P::prepare_g1(cs.ns(|| "Fifth prep"), &proof.a)?;
176 // pvk.h_gamma_pc
177 //&pvk.g_gamma_pc
178 let proof_b = proof.b.negate(cs.ns(|| "Negate b"))?;
179 let b_prep = P::prepare_g2(cs.ns(|| "Sixth prep"), &proof_b)?;
180 P::miller_loop(
181 cs.ns(|| "Miller loop 4"),
182 &[a_prep, pvk.g_gamma_pc.clone()],
183 &[pvk.h_gamma_pc.clone(), b_prep],
184 )?
185 };
186 let test2 = P::final_exponentiation(cs.ns(|| "Final Exp 2"), &test2_exp)?;
187
188 let one = P::GTGadget::one(cs.ns(|| "GT One"))?;
189 test1.enforce_equal(cs.ns(|| "Test 1"), &one)?;
190 test2.enforce_equal(cs.ns(|| "Test 2"), &one)?;
191 Ok(())
192 }
193}
194
195impl<PairingE, ConstraintF, P> AllocGadget<VerifyingKey<PairingE>, ConstraintF>
196 for VerifyingKeyGadget<PairingE, ConstraintF, P>
197where
198 PairingE: PairingEngine,
199 ConstraintF: Field,
200 P: PairingGadget<PairingE, ConstraintF>,
201{
202 #[inline]
203 fn alloc<FN, T, CS: ConstraintSystem<ConstraintF>>(
204 mut cs: CS,
205 value_gen: FN,
206 ) -> Result<Self, SynthesisError>
207 where
208 FN: FnOnce() -> Result<T, SynthesisError>,
209 T: Borrow<VerifyingKey<PairingE>>,
210 {
211 value_gen().and_then(|vk| {
212 let VerifyingKey {
213 h_g2,
214 g_alpha_g1,
215 h_beta_g2,
216 g_gamma_g1,
217 h_gamma_g2,
218 query,
219 } = vk.borrow().clone();
220 let h_g2 = P::G2Gadget::alloc(cs.ns(|| "h_g2"), || Ok(h_g2.into_projective()))?;
221 let g_alpha_g1 =
222 P::G1Gadget::alloc(cs.ns(|| "g_alpha"), || Ok(g_alpha_g1.into_projective()))?;
223 let h_beta_g2 =
224 P::G2Gadget::alloc(cs.ns(|| "h_beta"), || Ok(h_beta_g2.into_projective()))?;
225 let g_gamma_g1 =
226 P::G1Gadget::alloc(cs.ns(|| "g_gamma_g1"), || Ok(g_gamma_g1.into_projective()))?;
227 let h_gamma_g2 =
228 P::G2Gadget::alloc(cs.ns(|| "h_gamma_g2"), || Ok(h_gamma_g2.into_projective()))?;
229
230 let query = query
231 .into_iter()
232 .enumerate()
233 .map(|(i, query_i)| {
234 P::G1Gadget::alloc(cs.ns(|| format!("query_{}", i)), || {
235 Ok(query_i.into_projective())
236 })
237 })
238 .collect::<Vec<_>>()
239 .into_iter()
240 .collect::<Result<_, _>>()?;
241 Ok(Self {
242 h_g2,
243 g_alpha_g1,
244 h_beta_g2,
245 g_gamma_g1,
246 h_gamma_g2,
247 query,
248 })
249 })
250 }
251
252 #[inline]
253 fn alloc_input<FN, T, CS: ConstraintSystem<ConstraintF>>(
254 mut cs: CS,
255 value_gen: FN,
256 ) -> Result<Self, SynthesisError>
257 where
258 FN: FnOnce() -> Result<T, SynthesisError>,
259 T: Borrow<VerifyingKey<PairingE>>,
260 {
261 value_gen().and_then(|vk| {
262 let VerifyingKey {
263 h_g2,
264 g_alpha_g1,
265 h_beta_g2,
266 g_gamma_g1,
267 h_gamma_g2,
268 query,
269 } = vk.borrow().clone();
270 let h_g2 = P::G2Gadget::alloc_input(cs.ns(|| "h_g2"), || Ok(h_g2.into_projective()))?;
271 let g_alpha_g1 =
272 P::G1Gadget::alloc_input(cs.ns(|| "g_alpha"), || Ok(g_alpha_g1.into_projective()))?;
273 let h_beta_g2 =
274 P::G2Gadget::alloc_input(cs.ns(|| "h_beta"), || Ok(h_beta_g2.into_projective()))?;
275 let g_gamma_g1 = P::G1Gadget::alloc_input(cs.ns(|| "g_gamma_g1"), || {
276 Ok(g_gamma_g1.into_projective())
277 })?;
278 let h_gamma_g2 = P::G2Gadget::alloc_input(cs.ns(|| "h_gamma_g2"), || {
279 Ok(h_gamma_g2.into_projective())
280 })?;
281
282 let query = query
283 .into_iter()
284 .enumerate()
285 .map(|(i, query_i)| {
286 P::G1Gadget::alloc_input(cs.ns(|| format!("query_{}", i)), || {
287 Ok(query_i.into_projective())
288 })
289 })
290 .collect::<Vec<_>>()
291 .into_iter()
292 .collect::<Result<_, _>>()?;
293 Ok(Self {
294 h_g2,
295 g_alpha_g1,
296 h_beta_g2,
297 g_gamma_g1,
298 h_gamma_g2,
299 query,
300 })
301 })
302 }
303}
304
305impl<PairingE, ConstraintF, P> AllocGadget<Proof<PairingE>, ConstraintF>
306 for ProofGadget<PairingE, ConstraintF, P>
307where
308 PairingE: PairingEngine,
309 ConstraintF: Field,
310 P: PairingGadget<PairingE, ConstraintF>,
311{
312 #[inline]
313 fn alloc<FN, T, CS: ConstraintSystem<ConstraintF>>(
314 mut cs: CS,
315 value_gen: FN,
316 ) -> Result<Self, SynthesisError>
317 where
318 FN: FnOnce() -> Result<T, SynthesisError>,
319 T: Borrow<Proof<PairingE>>,
320 {
321 value_gen().and_then(|proof| {
322 let Proof { a, b, c } = proof.borrow().clone();
323 let a = P::G1Gadget::alloc_checked(cs.ns(|| "a"), || Ok(a.into_projective()))?;
324 let b = P::G2Gadget::alloc_checked(cs.ns(|| "b"), || Ok(b.into_projective()))?;
325 let c = P::G1Gadget::alloc_checked(cs.ns(|| "c"), || Ok(c.into_projective()))?;
326 Ok(Self { a, b, c })
327 })
328 }
329
330 #[inline]
331 fn alloc_input<FN, T, CS: ConstraintSystem<ConstraintF>>(
332 mut cs: CS,
333 value_gen: FN,
334 ) -> Result<Self, SynthesisError>
335 where
336 FN: FnOnce() -> Result<T, SynthesisError>,
337 T: Borrow<Proof<PairingE>>,
338 {
339 value_gen().and_then(|proof| {
340 let Proof { a, b, c } = proof.borrow().clone();
341 // We don't need to check here because the prime order check can be performed
342 // in plain.
343 let a = P::G1Gadget::alloc_input(cs.ns(|| "a"), || Ok(a.into_projective()))?;
344 let b = P::G2Gadget::alloc_input(cs.ns(|| "b"), || Ok(b.into_projective()))?;
345 let c = P::G1Gadget::alloc_input(cs.ns(|| "c"), || Ok(c.into_projective()))?;
346 Ok(Self { a, b, c })
347 })
348 }
349}
350
351impl<PairingE, ConstraintF, P> ToBytesGadget<ConstraintF>
352 for VerifyingKeyGadget<PairingE, ConstraintF, P>
353where
354 PairingE: PairingEngine,
355 ConstraintF: Field,
356 P: PairingGadget<PairingE, ConstraintF>,
357{
358 #[inline]
359 fn to_bytes<CS: ConstraintSystem<ConstraintF>>(
360 &self,
361 mut cs: CS,
362 ) -> Result<Vec<UInt8>, SynthesisError> {
363 let mut bytes = Vec::new();
364 bytes.extend_from_slice(&self.h_g2.to_bytes(&mut cs.ns(|| "h_g2 to bytes"))?);
365 bytes.extend_from_slice(
366 &self
367 .g_alpha_g1
368 .to_bytes(&mut cs.ns(|| "g_alpha_g1 to bytes"))?,
369 );
370 bytes.extend_from_slice(
371 &self
372 .h_beta_g2
373 .to_bytes(&mut cs.ns(|| "h_beta_g2 to bytes"))?,
374 );
375 bytes.extend_from_slice(
376 &self
377 .g_gamma_g1
378 .to_bytes(&mut cs.ns(|| "g_gamma_g1 to bytes"))?,
379 );
380 bytes.extend_from_slice(
381 &self
382 .h_gamma_g2
383 .to_bytes(&mut cs.ns(|| "h_gamma_g2 to bytes"))?,
384 );
385 for (i, q) in self.query.iter().enumerate() {
386 let mut cs = cs.ns(|| format!("Iteration {}", i));
387 bytes.extend_from_slice(&q.to_bytes(&mut cs.ns(|| "q"))?);
388 }
389 Ok(bytes)
390 }
391
392 fn to_bytes_strict<CS: ConstraintSystem<ConstraintF>>(
393 &self,
394 cs: CS,
395 ) -> Result<Vec<UInt8>, SynthesisError> {
396 self.to_bytes(cs)
397 }
398}
399
400#[cfg(test)]
401mod test {
402 use gm17::*;
403 use r1cs_core::{ConstraintSynthesizer, ConstraintSystem, SynthesisError};
404
405 use super::*;
406 use algebra::{
407 curves::bls12_377::Bls12_377,
408 fields::bls12_377::{Fq, Fr},
409 BitIterator, PrimeField,
410 };
411 use r1cs_std::{
412 boolean::Boolean, pairing::bls12_377::PairingGadget as Bls12_377PairingGadget,
413 test_constraint_system::TestConstraintSystem,
414 };
415 use rand::{thread_rng, Rng};
416
417 type TestProofSystem = Gm17<Bls12_377, Bench<Fr>, Fr>;
418 type TestVerifierGadget = Gm17VerifierGadget<Bls12_377, Fq, Bls12_377PairingGadget>;
419 type TestProofGadget = ProofGadget<Bls12_377, Fq, Bls12_377PairingGadget>;
420 type TestVkGadget = VerifyingKeyGadget<Bls12_377, Fq, Bls12_377PairingGadget>;
421
422 struct Bench<F: Field> {
423 inputs: Vec<Option<F>>,
424 num_constraints: usize,
425 }
426
427 impl<F: Field> ConstraintSynthesizer<F> for Bench<F> {
428 fn generate_constraints<CS: ConstraintSystem<F>>(
429 self,
430 cs: &mut CS,
431 ) -> Result<(), SynthesisError> {
432 assert!(self.inputs.len() >= 2);
433 assert!(self.num_constraints >= self.inputs.len());
434
435 let mut variables: Vec<_> = Vec::with_capacity(self.inputs.len());
436 for (i, input) in self.inputs.into_iter().enumerate() {
437 let input_var = cs.alloc_input(
438 || format!("Input {}", i),
439 || input.ok_or(SynthesisError::AssignmentMissing),
440 )?;
441 variables.push((input, input_var));
442 }
443
444 for i in 0..self.num_constraints {
445 let new_entry = {
446 let (input_1_val, input_1_var) = variables[i];
447 let (input_2_val, input_2_var) = variables[i + 1];
448 let result_val = input_1_val
449 .and_then(|input_1| input_2_val.map(|input_2| input_1 * &input_2));
450 let result_var = cs.alloc(
451 || format!("Result {}", i),
452 || result_val.ok_or(SynthesisError::AssignmentMissing),
453 )?;
454 cs.enforce(
455 || format!("Enforce constraint {}", i),
456 |lc| lc + input_1_var,
457 |lc| lc + input_2_var,
458 |lc| lc + result_var,
459 );
460 (result_val, result_var)
461 };
462 variables.push(new_entry);
463 }
464 Ok(())
465 }
466 }
467
468 #[test]
469 fn gm17_verifier_test() {
470 let num_inputs = 100;
471 let num_constraints = num_inputs;
472 let rng = &mut thread_rng();
473 let mut inputs: Vec<Option<Fr>> = Vec::with_capacity(num_inputs);
474 for _ in 0..num_inputs {
475 inputs.push(Some(rng.gen()));
476 }
477 let params = {
478 let c = Bench::<Fr> {
479 inputs: vec![None; num_inputs],
480 num_constraints,
481 };
482
483 generate_random_parameters(c, rng).unwrap()
484 };
485
486 {
487 let proof = {
488 // Create an instance of our circuit (with the
489 // witness)
490 let c = Bench {
491 inputs: inputs.clone(),
492 num_constraints,
493 };
494 // Create a gm17 proof with our parameters.
495 create_random_proof(c, ¶ms, rng).unwrap()
496 };
497
498 // assert!(!verify_proof(&pvk, &proof, &[a]).unwrap());
499 let mut cs = TestConstraintSystem::<Fq>::new();
500
501 let inputs: Vec<_> = inputs.into_iter().map(|input| input.unwrap()).collect();
502 let mut input_gadgets = Vec::new();
503
504 {
505 let mut cs = cs.ns(|| "Allocate Input");
506 for (i, input) in inputs.into_iter().enumerate() {
507 let mut input_bits = BitIterator::new(input.into_repr()).collect::<Vec<_>>();
508 // Input must be in little-endian, but BitIterator outputs in big-endian.
509 input_bits.reverse();
510
511 let input_bits =
512 Vec::<Boolean>::alloc_input(cs.ns(|| format!("Input {}", i)), || {
513 Ok(input_bits)
514 })
515 .unwrap();
516 input_gadgets.push(input_bits);
517 }
518 }
519
520 let vk_gadget = TestVkGadget::alloc_input(cs.ns(|| "Vk"), || Ok(¶ms.vk)).unwrap();
521 let proof_gadget =
522 TestProofGadget::alloc(cs.ns(|| "Proof"), || Ok(proof.clone())).unwrap();
523 println!("Time to verify!\n\n\n\n");
524 <TestVerifierGadget as NIZKVerifierGadget<TestProofSystem, Fq>>::check_verify(
525 cs.ns(|| "Verify"),
526 &vk_gadget,
527 input_gadgets.iter(),
528 &proof_gadget,
529 )
530 .unwrap();
531 if !cs.is_satisfied() {
532 println!("=========================================================");
533 println!("Unsatisfied constraints:");
534 println!("{:?}", cs.which_is_unsatisfied().unwrap());
535 println!("=========================================================");
536 }
537
538 // cs.print_named_objects();
539 assert!(cs.is_satisfied());
540 }
541 }
542}