plonk

Documentation

Overview

Package plonk implements PLONK Zero Knowledge Proof system.

See also

https://eprint.iacr.org/2019/953

Index

• func NewCS(curveID ecc.ID) constraint.ConstraintSystem
• func SRSSize(ccs constraint.ConstraintSystem) (sizeCanonical, sizeLagrange int)
• func Setup(ccs constraint.ConstraintSystem, srs, srsLagrange kzg.SRS) (ProvingKey, VerifyingKey, error)
• func Verify(proof Proof, vk VerifyingKey, publicWitness witness.Witness, ...) error
• type Proof
  • func NewProof(curveID ecc.ID) Proof
  • func Prove(ccs constraint.ConstraintSystem, pk ProvingKey, fullWitness witness.Witness, ...) (Proof, error)
• type ProvingKey
  • func NewProvingKey(curveID ecc.ID) ProvingKey
• type VerifyingKey
  • func NewVerifyingKey(curveID ecc.ID) VerifyingKey

Functions

func NewCS

func NewCS(curveID ecc.ID) constraint.ConstraintSystem

NewCS instantiate a concrete curved-typed SparseR1CS and return a ConstraintSystem interface This method exists for (de)serialization purposes

func SRSSize

func SRSSize(ccs constraint.ConstraintSystem) (sizeCanonical, sizeLagrange int)

SRSSize returns the required size of the kzg SRS for a given constraint system Note that the SRS size in Lagrange form is a power of 2, and the SRS size in canonical form need few extra elements (3) to account for the blinding factors

func Setup

func Setup(ccs constraint.ConstraintSystem, srs, srsLagrange kzg.SRS) (ProvingKey, VerifyingKey, error)

Setup prepares the public data associated to a circuit + public inputs. The kzg SRS must be provided in canonical and lagrange form. For test purposes, see test/unsafekzg package. With an existing SRS generated through MPC in canonical form, gnark-crypto offers the ToLagrangeG1 method to convert it to lagrange form.

func Verify

func Verify(proof Proof, vk VerifyingKey, publicWitness witness.Witness, opts ...backend.VerifierOption) error

Verify verifies a PLONK proof, from the proof, preprocessed public data, and public witness.

Types

type Proof

type Proof interface {
	io.WriterTo
	io.ReaderFrom
	gnarkio.WriterRawTo
}

Proof represents a Plonk proof generated by plonk.Prove

it's underlying implementation is curve specific (see gnark/internal/backend)

func NewProof

func NewProof(curveID ecc.ID) Proof

NewProof instantiates a curve-typed ProvingKey and returns an interface This function exists for serialization purposes

func Prove

func Prove(ccs constraint.ConstraintSystem, pk ProvingKey, fullWitness witness.Witness, opts ...backend.ProverOption) (Proof, error)

Prove generates PLONK proof from a circuit, associated preprocessed public data, and the witness if the force flag is set:

	will execute all the prover computations, even if the witness is invalid
 will produce an invalid proof
	internally, the solution vector to the SparseR1CS will be filled with random values which may impact benchmarking

type ProvingKey

type ProvingKey interface {
	io.WriterTo
	io.ReaderFrom
	gnarkio.WriterRawTo
	gnarkio.UnsafeReaderFrom
	VerifyingKey() interface{}
}

ProvingKey represents a plonk ProvingKey

it's underlying implementation is strongly typed with the curve (see gnark/internal/backend)

func NewProvingKey

func NewProvingKey(curveID ecc.ID) ProvingKey

NewProvingKey instantiates a curve-typed ProvingKey and returns an interface This function exists for serialization purposes

type VerifyingKey

type VerifyingKey interface {
	io.WriterTo
	io.ReaderFrom
	gnarkio.WriterRawTo
	gnarkio.UnsafeReaderFrom
	NbPublicWitness() int // number of elements expected in the public witness
	ExportSolidity(w io.Writer) error
}

VerifyingKey represents a plonk VerifyingKey

it's underlying implementation is strongly typed with the curve (see gnark/internal/backend)

func NewVerifyingKey

func NewVerifyingKey(curveID ecc.ID) VerifyingKey

NewVerifyingKey instantiates a curve-typed VerifyingKey and returns an interface This function exists for serialization purposes