Struct bbs::prover::Prover

pub struct Prover {}

This struct represents a Prover who receives signatures or proves with them. Provided are methods for 2PC where some are only known to the prover and a blind signature is created, unblinding signatures, verifying signatures, and creating signature proofs of knowledge with selective disclosure proofs

Implementations

impl Prover

pub fn new_link_secret() -> SignatureMessage

Generate a unique message that will be used across multiple signatures. This link_secret is the same in all signatures and allows a prover to demonstrate that signatures were issued to the same identity. This value should be a blinded message in all signatures and never revealed to anyone.

pub fn new_blind_signature_context(
    verkey: &PublicKey,
    messages: &BTreeMap<usize, SignatureMessage>,
    nonce: &ProofNonce
) -> Result<(BlindSignatureContext, SignatureBlinding), BBSError>

Create the structures need to send to an issuer to complete a blinded signature

pub fn complete_signature(
    verkey: &PublicKey,
    messages: &[SignatureMessage],
    blind_signature: &BlindSignature,
    blinding_factor: &SignatureBlinding
) -> Result<Signature, BBSError>

Unblinds and verifies a signature received from an issuer

pub fn commit_signature_pok(
    request: &ProofRequest,
    proof_messages: &[ProofMessage],
    signature: &Signature
) -> Result<PoKOfSignature, BBSError>

Create a new signature proof of knowledge and selective disclosure proof from a verifier's request

Arguments

• request - Proof request from verifier
• proof_messages - If blinding_factor is Some(Nonce) then it will use that. If None, a blinding factor will be generated at random.

pub fn create_challenge_hash(
    pok_sigs: &[PoKOfSignature],
    claims: Option<&[&[u8]]>,
    nonce: &ProofNonce
) -> Result<ProofChallenge, BBSError>

Create the challenge hash for a set of proofs

Arguments

• poks - a vec of PoKOfSignature objects
• nonce - a SignatureNonce
• claims - an optional slice of bytes the prover wishes to include in the challenge

pub fn generate_signature_pok(
    pok_sig: PoKOfSignature,
    challenge: &ProofChallenge
) -> Result<SignatureProof, BBSError>

Convert the a committed proof of signature knowledge to the proof