1#![allow(non_snake_case)]
  2#![allow(non_upper_case_globals)]
  3#![allow(non_camel_case_types)]
  4#![allow(clippy::upper_case_acronyms)]
  5
  6use ark_ec::CurveGroup;
  7use ark_ff::PrimeField;
  8use ark_std::rand::CryptoRng;
  9use ark_std::{fmt::Debug, rand::RngCore};
 10use thiserror::Error;
 11
 12use crate::frontend::FCircuit;
 13
 14pub mod ccs;
 15pub mod commitment;
 16pub mod constants;
 17pub mod folding;
 18pub mod frontend;
 19pub mod transcript;
 20pub mod utils;
 21
 22#[derive(Debug, Error)]
 23pub enum Error {
 24    // Wrappers on top of other errors
 25    #[error("ark_relations::r1cs::SynthesisError")]
 26    SynthesisError(#[from] ark_relations::r1cs::SynthesisError),
 27    #[error("ark_serialize::SerializationError")]
 28    SerializationError(#[from] ark_serialize::SerializationError),
 29    #[error("ark_poly_commit::Error")]
 30    PolyCommitError(#[from] ark_poly_commit::Error),
 31    #[error("crate::utils::espresso::virtual_polynomial::ArithErrors")]
 32    ArithError(#[from] utils::espresso::virtual_polynomial::ArithErrors),
 33    #[error(transparent)]
 34    ProtoGalaxy(folding::protogalaxy::ProtoGalaxyError),
 35    #[error("{0}")]
 36    Other(String),
 37
 38    // Relation errors
 39    #[error("Relation not satisfied")]
 40    NotSatisfied,
 41    #[error("SNARK verification failed")]
 42    SNARKVerificationFail,
 43    #[error("IVC verification failed")]
 44    IVCVerificationFail,
 45    #[error("R1CS instance is expected to not be relaxed")]
 46    R1CSUnrelaxedFail,
 47    #[error("Could not find the inner ConstraintSystem")]
 48    NoInnerConstraintSystem,
 49    #[error("Sum-check prove failed: {0}")]
 50    SumCheckProveError(String),
 51    #[error("Sum-check verify failed: {0}")]
 52    SumCheckVerifyError(String),
 53
 54    // Comparators errors
 55    #[error("Not equal")]
 56    NotEqual,
 57    #[error("Vectors should have the same length ({0}: {1}, {2}: {3})")]
 58    NotSameLength(String, usize, String, usize),
 59    #[error("Vector's length ({0}) is not the expected ({1})")]
 60    NotExpectedLength(usize, usize),
 61    #[error("Vector ({0}) length ({1}) is not a power of two")]
 62    NotPowerOfTwo(String, usize),
 63    #[error("Can not be empty")]
 64    Empty,
 65    #[error("Value out of bounds")]
 66    OutOfBounds,
 67    #[error("Could not construct the Evaluation Domain")]
 68    NewDomainFail,
 69
 70    // Commitment errors
 71    #[error("Pedersen parameters length is not sufficient (generators.len={0} < vector.len={1} unsatisfied)")]
 72    PedersenParamsLen(usize, usize),
 73    #[error("Blinding factor not 0 for Commitment without hiding")]
 74    BlindingNotZero,
 75    #[error("Commitment verification failed")]
 76    CommitmentVerificationFail,
 77
 78    // Other
 79    #[error("Randomness for blinding not found")]
 80    MissingRandomness,
 81    #[error("Missing value: {0}")]
 82    MissingValue(String),
 83    #[error("Feature '{0}' not supported yet")]
 84    NotSupportedYet(String),
 85    #[error("Feature '{0}' is not supported and it will not be")]
 86    NotSupported(String),
 87    #[error("max i-th step reached (usize limit reached)")]
 88    MaxStep,
 89}
 90
 91/// FoldingScheme defines trait that is implemented by the diverse folding schemes. It is defined
 92/// over a cycle of curves (C1, C2), where:
 93/// - C1 is the main curve, which ScalarField we use as our F for al the field operations
 94/// - C2 is the auxiliary curve, which we use for the commitments, whose BaseField (for point
 95/// coordinates) are in the C1::ScalarField.
 96/// In other words, C1.Fq == C2.Fr, and C1.Fr == C2.Fq.
 97pub trait FoldingScheme<C1: CurveGroup, C2: CurveGroup, FC>: Clone + Debug
 98where
 99    C1: CurveGroup<BaseField = C2::ScalarField, ScalarField = C2::BaseField>,
100    C2::BaseField: PrimeField,
101    FC: FCircuit<C1::ScalarField>,
102{
103    type PreprocessorParam: Debug;
104    type ProverParam: Debug;
105    type VerifierParam: Debug;
106    type CommittedInstanceWithWitness: Debug;
107    type CFCommittedInstanceWithWitness: Debug; // CycleFold CommittedInstance & Witness
108
109    fn preprocess(
110        prep_param: &Self::PreprocessorParam,
111    ) -> Result<(Self::ProverParam, Self::VerifierParam), Error>;
112
113    fn init(
114        pp: &Self::ProverParam,
115        step_circuit: FC,
116        z_0: Vec<C1::ScalarField>, // initial state
117    ) -> Result<Self, Error>;
118
119    fn prove_step(&mut self) -> Result<(), Error>;
120
121    // returns the state at the current step
122    fn state(&self) -> Vec<C1::ScalarField>;
123
124    // returns the instances at the current step, in the following order:
125    // (running_instance, incoming_instance, cyclefold_instance)
126    fn instances(
127        &self,
128    ) -> (
129        Self::CommittedInstanceWithWitness,
130        Self::CommittedInstanceWithWitness,
131        Self::CFCommittedInstanceWithWitness,
132    );
133
134    fn verify(
135        vp: Self::VerifierParam,
136        z_0: Vec<C1::ScalarField>, // initial state
137        z_i: Vec<C1::ScalarField>, // last state
138        // number of steps between the initial state and the last state
139        num_steps: C1::ScalarField,
140        running_instance: Self::CommittedInstanceWithWitness,
141        incoming_instance: Self::CommittedInstanceWithWitness,
142        cyclefold_instance: Self::CFCommittedInstanceWithWitness,
143    ) -> Result<(), Error>;
144}
145
146pub trait Decider<
147    C1: CurveGroup,
148    C2: CurveGroup,
149    FC: FCircuit<C1::ScalarField>,
150    FS: FoldingScheme<C1, C2, FC>,
151> where
152    C1: CurveGroup<BaseField = C2::ScalarField, ScalarField = C2::BaseField>,
153    C2::BaseField: PrimeField,
154{
155    type ProverParam: Clone;
156    type Proof;
157    type VerifierParam;
158    type PublicInput: Debug;
159    type CommittedInstanceWithWitness: Debug;
160    type CommittedInstance: Clone + Debug;
161
162    fn prove(
163        pp: Self::ProverParam,
164        rng: impl RngCore + CryptoRng,
165        folding_scheme: FS,
166    ) -> Result<Self::Proof, Error>;
167
168    fn verify(
169        vp: Self::VerifierParam,
170        i: C1::ScalarField,
171        z_0: Vec<C1::ScalarField>,
172        z_i: Vec<C1::ScalarField>,
173        running_instance: &Self::CommittedInstance,
174        incoming_instance: &Self::CommittedInstance,
175        proof: Self::Proof,
176        // returns `Result<bool, Error>` to differentiate between an error occurred while performing
177        // the verification steps, and the verification logic of the scheme not passing.
178    ) -> Result<bool, Error>;
179}