hash-chain-sonobe/src/sha_chain.rs
src/sha_chain.rsRaw
1///
2/// This example performs the full flow:
3/// - define the circuit to be folded
4/// - fold the circuit with Nova+CycleFold's IVC
5/// - generate a DeciderEthCircuit final proof
6/// - generate the Solidity contract that verifies the proof
7/// - verify the proof in the EVM
8///
9
10#[cfg(test)]
11mod tests {
12 use ark_bn254::{constraints::GVar, Bn254, Fr, G1Projective as G1};
13 use ark_grumpkin::{constraints::GVar as GVar2, Projective as G2};
14
15 use ark_groth16::Groth16;
16
17 use ark_ff::PrimeField;
18
19 use std::time::Instant;
20
21 use ark_crypto_primitives::crh::sha256::{constraints::Sha256Gadget, digest::Digest, Sha256};
22 use ark_r1cs_std::fields::fp::FpVar;
23 use ark_r1cs_std::{bits::uint8::UInt8, boolean::Boolean, ToBitsGadget, ToBytesGadget};
24 use ark_relations::r1cs::{ConstraintSystemRef, SynthesisError};
25 use std::marker::PhantomData;
26
27 use folding_schemes::{
28 commitment::{kzg::KZG, pedersen::Pedersen},
29 folding::nova::{
30 decider_eth::{prepare_calldata, Decider as DeciderEth},
31 Nova, PreprocessorParam,
32 },
33 frontend::FCircuit,
34 transcript::poseidon::poseidon_canonical_config,
35 Decider, Error, FoldingScheme,
36 };
37 use solidity_verifiers::{
38 utils::get_function_selector_for_nova_cyclefold_verifier,
39 verifiers::nova_cyclefold::get_decider_template_for_cyclefold_decider,
40 NovaCycleFoldVerifierKey,
41 };
42
43 use crate::utils::tests::*;
44
45 /// Test circuit to be folded
46 #[derive(Clone, Copy, Debug)]
47 pub struct SHA256FoldStepCircuit<F: PrimeField> {
48 _f: PhantomData<F>,
49 }
50 impl<F: PrimeField> FCircuit<F> for SHA256FoldStepCircuit<F> {
51 type Params = ();
52 fn new(_params: Self::Params) -> Result<Self, Error> {
53 Ok(Self { _f: PhantomData })
54 }
55 fn state_len(&self) -> usize {
56 32
57 }
58 fn external_inputs_len(&self) -> usize {
59 0
60 }
61 // function to compute the next state of the folding via rust-native code (not Circom). Used to
62 // check the Circom values.
63 fn step_native(
64 &self,
65 _i: usize,
66 z_i: Vec<F>,
67 _external_inputs: Vec<F>,
68 ) -> Result<Vec<F>, Error> {
69 let b = f_vec_to_bytes(z_i.to_vec());
70 let mut sha256 = Sha256::default();
71 sha256.update(b);
72 let z_i1 = sha256.finalize().to_vec();
73
74 bytes_to_f_vec(z_i1.to_vec())
75 }
76 fn generate_step_constraints(
77 &self,
78 _cs: ConstraintSystemRef<F>,
79 _i: usize,
80 z_i: Vec<FpVar<F>>,
81 _external_inputs: Vec<FpVar<F>>,
82 ) -> Result<Vec<FpVar<F>>, SynthesisError> {
83 let mut sha256_var = Sha256Gadget::default();
84 let z_i_u8: Vec<UInt8<F>> = z_i
85 .iter()
86 .map(|f| UInt8::<F>::from_bits_le(&f.to_bits_le().unwrap()[..8]))
87 .collect::<Vec<_>>();
88 sha256_var.update(&z_i_u8).unwrap();
89 let z_i1_u8 = sha256_var.finalize()?.to_bytes()?;
90 let z_i1: Vec<FpVar<F>> = z_i1_u8
91 .iter()
92 .map(|e| {
93 let bits = e.to_bits_le().unwrap();
94 Boolean::<F>::le_bits_to_fp_var(&bits).unwrap()
95 })
96 .collect();
97
98 Ok(z_i1)
99 }
100 }
101
102 #[test]
103 fn full_flow() {
104 // set how many steps of folding we want to compute
105 let n_steps = 100;
106
107 // set the initial state
108 // let z_0_aux: Vec<u32> = vec![0_u32; 32 * 8];
109 let z_0_aux: Vec<u8> = vec![0_u8; 32];
110 let z_0: Vec<Fr> = z_0_aux.iter().map(|v| Fr::from(*v)).collect::<Vec<Fr>>();
111
112 let f_circuit = SHA256FoldStepCircuit::<Fr>::new(()).unwrap();
113
114 // ----------------
115 // Sanity check
116 // check that the f_circuit produces valid R1CS constraints
117 use ark_r1cs_std::alloc::AllocVar;
118 use ark_r1cs_std::fields::fp::FpVar;
119 use ark_r1cs_std::R1CSVar;
120 use ark_relations::r1cs::ConstraintSystem;
121 let cs = ConstraintSystem::<Fr>::new_ref();
122 let z_0_var = Vec::<FpVar<Fr>>::new_witness(cs.clone(), || Ok(z_0.clone())).unwrap();
123 let z_1_var = f_circuit
124 .generate_step_constraints(cs.clone(), 1, z_0_var, vec![])
125 .unwrap();
126 // check z_1_var against the native z_1
127 let z_1_native = f_circuit.step_native(1, z_0.clone(), vec![]).unwrap();
128 assert_eq!(z_1_var.value().unwrap(), z_1_native);
129 // check that the constraint system is satisfied
130 assert!(cs.is_satisfied().unwrap());
131 // ----------------
132
133 // define type aliases to avoid writting the whole type each time
134 pub type N = Nova<
135 G1,
136 GVar,
137 G2,
138 GVar2,
139 SHA256FoldStepCircuit<Fr>,
140 KZG<'static, Bn254>,
141 Pedersen<G2>,
142 false,
143 >;
144 pub type D = DeciderEth<
145 G1,
146 GVar,
147 G2,
148 GVar2,
149 SHA256FoldStepCircuit<Fr>,
150 KZG<'static, Bn254>,
151 Pedersen<G2>,
152 Groth16<Bn254>,
153 N,
154 >;
155
156 let poseidon_config = poseidon_canonical_config::<Fr>();
157 let mut rng = rand::rngs::OsRng;
158
159 // prepare the Nova prover & verifier params
160 let nova_preprocess_params = PreprocessorParam::new(poseidon_config, f_circuit);
161 let start = Instant::now();
162 let nova_params = N::preprocess(&mut rng, &nova_preprocess_params).unwrap();
163 println!("Nova params generated: {:?}", start.elapsed());
164
165 // initialize the folding scheme engine, in our case we use Nova
166 let mut nova = N::init(&nova_params, f_circuit, z_0.clone()).unwrap();
167
168 // prepare the Decider prover & verifier params
169 let start = Instant::now();
170 let (decider_pp, decider_vp) = D::preprocess(&mut rng, &nova_params, nova.clone()).unwrap();
171 println!("Decider params generated: {:?}", start.elapsed());
172
173 // run n steps of the folding iteration
174 let start_full = Instant::now();
175 for _ in 0..n_steps {
176 let start = Instant::now();
177 nova.prove_step(rng, vec![], None).unwrap();
178 println!(
179 "Nova::prove_step (sha256) {}: {:?}",
180 nova.i,
181 start.elapsed()
182 );
183 }
184 println!("Nova's all steps time: {:?}", start_full.elapsed());
185
186 // ----------------
187 // Sanity check
188 // The following lines contain a sanity check that checks the IVC proof (before going into
189 // the zkSNARK proof)
190 let (running_instance, incoming_instance, cyclefold_instance) = nova.instances();
191 N::verify(
192 nova_params.1, // Nova's verifier params
193 z_0,
194 nova.z_i.clone(),
195 nova.i,
196 running_instance,
197 incoming_instance,
198 cyclefold_instance,
199 )
200 .unwrap();
201 // ----------------
202
203 let rng = rand::rngs::OsRng;
204 let start = Instant::now();
205 let proof = D::prove(rng, decider_pp, nova.clone()).unwrap();
206 println!("generated Decider proof: {:?}", start.elapsed());
207
208 let verified = D::verify(
209 decider_vp.clone(),
210 nova.i,
211 nova.z_0.clone(),
212 nova.z_i.clone(),
213 &nova.U_i,
214 &nova.u_i,
215 &proof,
216 )
217 .unwrap();
218 assert!(verified);
219 println!("Decider proof verification: {}", verified);
220
221 // generate the Solidity code that verifies this Decider final proof
222 let function_selector =
223 get_function_selector_for_nova_cyclefold_verifier(nova.z_0.len() * 2 + 1);
224
225 let calldata: Vec<u8> = prepare_calldata(
226 function_selector,
227 nova.i,
228 nova.z_0,
229 nova.z_i,
230 &nova.U_i,
231 &nova.u_i,
232 proof,
233 )
234 .unwrap();
235
236 // prepare the setup params for the solidity verifier
237 let nova_cyclefold_vk = NovaCycleFoldVerifierKey::from((decider_vp, f_circuit.state_len()));
238
239 // generate the solidity code
240 let decider_solidity_code = get_decider_template_for_cyclefold_decider(nova_cyclefold_vk);
241
242 /*
243 * Note: since we're proving the SHA256 (ie. 32 byte size, 256 bits), the number of inputs
244 * is too big for the contract. In a real world use case we would convert the binary
245 * representation into a couple of field elements which would be inputs of the Decider
246 * circuit, and in-circuit we would obtain the binary representation to be used for the
247 * final proof check.
248 *
249 * The following code is commented out for that reason.
250 // verify the proof against the solidity code in the EVM
251 use solidity_verifiers::evm::{compile_solidity, Evm};
252 let nova_cyclefold_verifier_bytecode =
253 compile_solidity(&decider_solidity_code, "NovaDecider");
254 let mut evm = Evm::default();
255 let verifier_address = evm.create(nova_cyclefold_verifier_bytecode);
256 let (_, output) = evm.call(verifier_address, calldata.clone());
257 assert_eq!(*output.last().unwrap(), 1);
258 */
259
260 // save smart contract and the calldata
261 println!("storing nova-verifier.sol and the calldata into files");
262 use std::fs;
263 fs::create_dir_all("./solidity").unwrap();
264 fs::write(
265 "./solidity/nova-verifier.sol",
266 decider_solidity_code.clone(),
267 )
268 .unwrap();
269 fs::write("./solidity/solidity-calldata.calldata", calldata.clone()).unwrap();
270 let s = solidity_verifiers::utils::get_formatted_calldata(calldata.clone());
271 fs::write("./solidity/solidity-calldata.inputs", s.join(",\n")).expect("");
272 }
273}