Crate p3_challenger 

p3-challenger

A Fiat–Shamir transcript and challenger framework, used to derive random challenges from an IOP’s transcript.

Key items:

• CanObserve, CanSample, CanSampleBits, FieldChallenger — the observe/sample trait family
• DuplexChallenger — sponge-based challenger over a cryptographic permutation
• HashChallenger — challenger built from a generic hash function
• MultiField32Challenger, SerializingChallenger32/64 — challengers bridging fields of different sizes
• GrindingChallenger — proof-of-work witness generation and verification

Prover and verifier must observe and sample in the exact same order; every proof object is bound to the transcript before any challenge it influences is sampled.

Part of Plonky3, dual-licensed under MIT and Apache 2.0.

Structs

DuplexChallenger

A generic duplex sponge challenger over a finite field, used for generating deterministic challenges from absorbed inputs.

HashChallenger

A generic challenger that uses a cryptographic hash function to generate challenges.

MultiField32Challenger

A challenger that samples in F: PrimeField32 while the transcript sponge lives in PF.

ResamplingError

Custom error raised when resampling is required for uniform bits but disabled via ErrorOnRejection strategy.

SerializingChallenger32

Given a challenger that can observe and sample bytes, produces a challenger that is able to sample and observe field elements of a PrimeField32.

SerializingChallenger64

Given a challenger that can observe and sample bytes, produces a challenger that is able to sample and observe field elements of a PrimeField64 field.

Traits

CanFinalizeDigest

Extract a binding commitment to the full transcript state.

CanObserve

A generic trait for absorbing elements into the transcript.

CanSample

A trait for sampling challenge elements from the Fiat-Shamir transcript.

CanSampleBits

A trait for sampling random bitstrings from the Fiat-Shamir transcript.

CanSampleUniformBits

Uniform bit sampling interface.

FieldChallenger

A high-level trait combining observation and sampling over a finite field.

GrindingChallenger

Trait for challengers that support proof-of-work (PoW) grinding.

UniformGrindingChallenger

Trait for challengers that support proof-of-work (PoW) grinding with guaranteed uniformly sampled bits.

UniformSamplingField

Trait for fields that support uniform bit sampling optimizations