Struct blindsign::session::BlindSession

pub struct BlindSession { /* fields omitted */ }

For managing the signer side response to incoming requests for blind signatures. How the actual requests come in is orthogonal to this crate.

Methods

impl BlindSession

pub fn new() -> Result<([u8; 32], Self)>

Initiate a new signer side session to create a blind signature for a requester.

Returns

• Ok( ([u8; 32], BlindSession) ) on success, with the [u8; 32] being the value R' for sending to the requester, and the BlindSession struct supporting the sign_ep() method for completing the protocol (upon the receipt of the E' response from the requester).

• Err(::Error) variant on failure, which is only due to the failure to initiate the internal random number generator.

Mathematics

• R' = kP
• k = A randomly generated scalar by the signer
• P = An ECC Generator Point

pub fn sign_ep(self, ep: &[u8; 32], xs: Scalar) -> Result<[u8; 32]>

Consumes the session and returns the generated blind signature.

Arguments

• 'ep' - A reference to a 32 byte scalar represented as a [u8; 32]. This scalar is received from the requester in some manner.

• 'xs' - The private key componenet of the associated BlindKeypair component, in internal Scalar form. This is used for creating signatures which can be authenticated with the associated public key.

Returns

• Ok([u8; 32]) on success, representing the completed blind signature value S'.

• Err(errors::BlindErrors) variant on error. Only errors if the requester provided a malformed scalar value ep.

Mathematics

• S' = Xs*e' + k
• e' = requester calculated e' value, received by signer
• k = randomly generated number by the signer