Struct FnDsaExpandedKey 

pub struct FnDsaExpandedKey { /* private fields */ }

A precomputed Falcon signing tree for fast repeated signing.

Expanding a private key takes ~2.5× longer than a single sign operation, but each subsequent sign/sign_deterministic call is ~1.5× faster (no re-expansion). Use this when signing many messages with the same key.

The expanded key bytes are automatically zeroized on drop.

Example

use falcon::prelude::*;

let kp = FnDsaKeyPair::generate(9).unwrap();
let ek = kp.expand().unwrap();

let sig = ek.sign(b"message", &DomainSeparation::None).unwrap();
FnDsaSignature::verify(sig.to_bytes(), ek.public_key(), b"message",
    &DomainSeparation::None).unwrap();

Implementations

impl FnDsaExpandedKey

pub fn sign( &self, message: &[u8], domain: &DomainSeparation<'_>, ) -> Result<FnDsaSignature, FalconError>

Sign a message using OS entropy.

pub fn sign_deterministic( &self, message: &[u8], sign_seed: &[u8], domain: &DomainSeparation<'_>, ) -> Result<FnDsaSignature, FalconError>

Sign a message deterministically from a seed (for testing / no_std).

pub fn public_key(&self) -> &[u8]

The public key corresponding to this expanded key.

pub fn logn(&self) -> u32

The logn parameter (9 = FN-DSA-512, 10 = FN-DSA-1024).

Trait Implementations

impl Clone for FnDsaExpandedKey

fn clone(&self) -> FnDsaExpandedKey

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for FnDsaExpandedKey

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.