merge SharePackage into SecretShare

frost-core/src/frost/keys.rs

@@ -233,13 +233,17 @@ pub struct VerifiableSecretSharingCommitment<C: Ciphersuite>(
     pub(super) Vec<CoefficientCommitment<C>>,
 );
 
-/// A secret share generated by performing a (t-out-of-n) secret sharing scheme.
+/// A secret share generated by performing a (t-out-of-n) secret sharing scheme,
+/// generated by a dealer performing [`keygen_with_dealer`].
 ///
 /// `n` is the total number of shares and `t` is the threshold required to reconstruct the secret;
 /// in this case we use Shamir's secret sharing.
 ///
 /// As a solution to the secret polynomial _f_ (a 'point'), the `identifier` is the x-coordinate, and the
 /// `value` is the y-coordinate.
+///
+/// To derive a FROST keypair, the receiver of the [`SecretShare`] *must* call
+/// .into(), which under the hood also performs validation.
 #[derive(Clone, Zeroize)]
 pub struct SecretShare<C: Ciphersuite> {
     /// The participant identifier of this [`SecretShare`].
@@ -298,19 +302,6 @@ where
     }
 }
 
-/// Secret and public key material generated by a dealer performing
-/// [`keygen_with_dealer`].
-///
-/// To derive a FROST keypair, the receiver of the [`SharePackage`] *must* call
-/// .into(), which under the hood also performs validation.
-#[derive(Clone)]
-pub struct SharePackage<C: Ciphersuite> {
-    /// Denotes the participant identifier each share is owned by.
-    pub identifier: Identifier<C>,
-    /// This participant's secret share.
-    pub secret_share: SecretShare<C>,
-}
-
 /// Allows all participants' keys to be generated using a central, trusted
 /// dealer.
 ///
@@ -327,7 +318,7 @@ pub fn keygen_with_dealer<C: Ciphersuite, R: RngCore + CryptoRng>(
     num_signers: u8,
     threshold: u8,
     mut rng: R,
-) -> Result<(Vec<SharePackage<C>>, PublicKeyPackage<C>), &'static str> {
+) -> Result<(Vec<SecretShare<C>>, PublicKeyPackage<C>), &'static str> {
     let mut bytes = [0; 64];
     rng.fill_bytes(&mut bytes);
 
@@ -337,23 +328,16 @@ pub fn keygen_with_dealer<C: Ciphersuite, R: RngCore + CryptoRng>(
     let coefficients = generate_coefficients::<C, R>(threshold as usize - 1, rng);
 
     let secret_shares = generate_secret_shares(&secret, num_signers, threshold, coefficients)?;
-    let mut share_packages: Vec<SharePackage<C>> = Vec::with_capacity(num_signers as usize);
     let mut signer_pubkeys: HashMap<Identifier<C>, VerifyingShare<C>> =
         HashMap::with_capacity(num_signers as usize);
 
-    for secret_share in secret_shares {
+    for secret_share in &secret_shares {
         let signer_public = secret_share.value.into();
-
-        share_packages.push(SharePackage {
-            identifier: secret_share.identifier,
-            secret_share: secret_share.clone(),
-        });
-
         signer_pubkeys.insert(secret_share.identifier, signer_public);
     }
 
     Ok((
-        share_packages,
+        secret_shares,
         PublicKeyPackage {
             signer_pubkeys,
             group_public,
@@ -364,7 +348,7 @@ pub fn keygen_with_dealer<C: Ciphersuite, R: RngCore + CryptoRng>(
 /// A FROST keypair, which can be generated either by a trusted dealer or using
 /// a DKG.
 ///
-/// When using a central dealer, [`SharePackage`]s are distributed to
+/// When using a central dealer, [`SecretShare`]s are distributed to
 /// participants, who then perform verification, before deriving
 /// [`KeyPackage`]s, which they store to later use during signing.
 #[derive(Clone)]
@@ -404,7 +388,7 @@ where
     }
 }
 
-impl<C> TryFrom<SharePackage<C>> for KeyPackage<C>
+impl<C> TryFrom<SecretShare<C>> for KeyPackage<C>
 where
     C: Ciphersuite,
 {
@@ -412,18 +396,18 @@ where
 
     /// Tries to verify a share and construct a [`KeyPackage`] from it.
     ///
-    /// When participants receive a [`SharePackage`] from the dealer, they
+    /// When participants receive a [`SecretShare`] from the dealer, they
     /// *MUST* verify the integrity of the share before continuing on to
     /// transform it into a signing/verification keypair. Here, we assume that
     /// every participant has the same view of the commitment issued by the
     /// dealer, but implementations *MUST* make sure that all participants have
     /// a consistent view of this commitment in practice.
-    fn try_from(share_package: SharePackage<C>) -> Result<Self, &'static str> {
-        let (public, group_public) = share_package.secret_share.verify()?;
+    fn try_from(secret_share: SecretShare<C>) -> Result<Self, &'static str> {
+        let (public, group_public) = secret_share.verify()?;
 
         Ok(KeyPackage {
-            identifier: share_package.identifier,
-            secret_share: share_package.secret_share.value,
+            identifier: secret_share.identifier,
+            secret_share: secret_share.value,
             public,
             group_public,
         })

frost-core/src/tests.rs

@@ -121,7 +121,7 @@ pub fn check_sign_with_dealer<C: Ciphersuite, R: RngCore + CryptoRng>(mut rng: R
         .is_ok());
 
     // Check that the threshold signature can be verified by the group public
-    // key (the verification key) from SharePackage.group_public
+    // key (the verification key) from KeyPackage.group_public
     for (participant_identifier, _) in nonces.clone() {
         let key_package = key_packages.get(&participant_identifier).unwrap();
 

frost-p256/src/lib.rs

@@ -237,12 +237,12 @@ pub mod keys {
         num_signers: u8,
         threshold: u8,
         mut rng: RNG,
-    ) -> Result<(Vec<SharePackage>, PublicKeyPackage), &'static str> {
+    ) -> Result<(Vec<SecretShare>, PublicKeyPackage), &'static str> {
         frost::keys::keygen_with_dealer(num_signers, threshold, &mut rng)
     }
 
     ///
-    pub type SharePackage = frost::keys::SharePackage<P>;
+    pub type SecretShare = frost::keys::SecretShare<P>;
 
     ///
     pub type KeyPackage = frost::keys::KeyPackage<P>;

frost-ristretto255/src/lib.rs

@@ -215,7 +215,7 @@ pub mod keys {
         num_signers: u8,
         threshold: u8,
         mut rng: RNG,
-    ) -> Result<(Vec<SharePackage>, PublicKeyPackage), &'static str> {
+    ) -> Result<(Vec<SecretShare>, PublicKeyPackage), &'static str> {
         frost::keys::keygen_with_dealer(num_signers, threshold, &mut rng)
     }
 
@@ -224,14 +224,14 @@ pub mod keys {
     ///
     /// # Security
     ///
-    /// To derive a FROST(ristretto255, SHA-512) keypair, the receiver of the [`SharePackage`] *must* call
+    /// To derive a FROST(ristretto255, SHA-512) keypair, the receiver of the [`SecretShare`] *must* call
     /// .into(), which under the hood also performs validation.
-    pub type SharePackage = frost::keys::SharePackage<R>;
+    pub type SecretShare = frost::keys::SecretShare<R>;
 
     /// A FROST(ristretto255, SHA-512) keypair, which can be generated either by a trusted dealer or using
     /// a DKG.
     ///
-    /// When using a central dealer, [`SharePackage`]s are distributed to
+    /// When using a central dealer, [`SecretShare`]s are distributed to
     /// participants, who then perform verification, before deriving
     /// [`KeyPackage`]s, which they store to later use during signing.
     pub type KeyPackage = frost::keys::KeyPackage<R>;