Struct Transcript 

pub struct Transcript<B: Boolean> { /* private fields */ }

A transcript of a public-coin argument.

The prover’s messages are added to the transcript using append_message, and the verifier’s challenges can be computed using challenge_bytes.

Creating and using a Merlin transcript

To create a Merlin transcript, use Transcript::new(). This function takes a domain separation label which should be unique to the application.

To use the transcript with a Merlin-based proof implementation, the prover’s side creates a Merlin transcript with an application-specific domain separation label, and passes a &mut reference to the transcript to the proving function(s).

To verify the resulting proof, the verifier creates their own Merlin transcript using the same domain separation label, then passes a &mut reference to the verifier’s transcript to the verification function.

Implementing proofs using Merlin

For information on the design of Merlin and how to use it to implement a proof system, see the documentation at merlin.cool, particularly the Using Merlin section.

Implementations

impl<B: Boolean> Transcript<B>

pub fn new(label: &'static [u8]) -> Transcript<B>

Initialize a new transcript with the supplied label, which is used as a domain separator.

Note

This function should be called by a proof library’s API consumer (i.e., the application using the proof library), and not by the proof implementation. See the Passing Transcripts section of the Merlin website for more details on why.

pub fn append_message(&mut self, label: &'static [u8], message: &[Byte<B>])

Append a prover’s message to the transcript.

The label parameter is metadata about the message, and is also appended to the transcript. See the Transcript Protocols section of the Merlin website for details on labels.

pub fn challenge_bytes(&mut self, label: &'static [u8], dest: &mut [Byte<B>])

Fill the supplied buffer with the verifier’s challenge bytes.

The label parameter is metadata about the challenge, and is also appended to the transcript. See the Transcript Protocols section of the Merlin website for details on labels.

pub fn range_proof_domain_separator(&mut self, n: u64)

pub fn inner_product_proof_domain_separator(&mut self, n: u64)

pub fn ciphertext_commitment_equality_proof_domain_separator(&mut self)

pub fn zero_ciphertext_proof_domain_separator(&mut self)

pub fn grouped_ciphertext_validity_proof_domain_separator( &mut self, handles: u64, )

pub fn batched_grouped_ciphertext_validity_proof_domain_separator( &mut self, handles: u64, )

pub fn percentage_with_cap_proof_domain_separator(&mut self)

pub fn pubkey_proof_domain_separator(&mut self)

impl Transcript<BooleanValue>

pub fn append_scalar( &mut self, label: &'static [u8], scalar: &FieldValue<ScalarField>, )

pub fn append_point( &mut self, label: &'static [u8], point: &CompressedCurveValue, )

pub fn append_elgamal_ciphertext( &mut self, label: &'static [u8], ciphertext: &ElGamalCiphertext, )

pub fn append_elgamal_ciphertext_2_handles( &mut self, label: &'static [u8], ciphertext: &GroupedElGamalCiphertext2Handles, )

pub fn append_elgamal_ciphertext_3_handles( &mut self, label: &'static [u8], ciphertext: &GroupedElGamalCiphertext3Handles, )

pub fn challenge_scalar( &mut self, label: &'static [u8], ) -> FieldValue<ScalarField>

Trait Implementations

impl<B: Clone + Boolean> Clone for Transcript<B>

fn clone(&self) -> Transcript<B>

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.