WIP: Implement COCKTAIL-DKG

Cargo.toml

@@ -16,7 +16,7 @@ members = [
 # If you update the edition, make sure to also update the argument to rustfmt
 # in gencode/src/main.rs.
 edition = "2021"
-rust-version = "1.81"
+rust-version = "1.85"
 version = "3.0.0-rc.0"
 authors = [
     "Deirdre Connolly <durumcrustulum@gmail.com>",
@@ -31,6 +31,8 @@ categories = ["cryptography"]
 [workspace.dependencies]
 # Currently holding back from updating due to MSRV 1.86 of criterion 0.8
 # (we don't want to raise our MSRV just for this)
+chacha20poly1305 = { version = "0.10", default-features = false, features = ["alloc"] }
+xaes-256-gcm = { version = "0.1.0-rc.3", default-features = false, features = ["alloc"] }
 criterion = "0.6"
 document-features = "0.2.7"
 hex = { version  = "0.4.3", default-features = false, features = ["alloc"] }

frost-core/Cargo.toml

@@ -21,6 +21,7 @@ const-crc32 = { version = "1.2.0", package = "const-crc32-nostd" }
 document-features.workspace = true
 debugless-unwrap = { version = "1.0.0", optional = true }
 derive-getters = "0.5.0"
+derive-new = "0.6"
 hex.workspace = true
 postcard = { version = "1.0.0", features = ["alloc"], optional = true }
 rand_core = { version = "0.6", default-features = false }
@@ -63,6 +64,8 @@ internals = []
 ## `serde` (e.g. JSON with `serde_json`).
 serde = ["dep:serde", "dep:serdect"]
 serialization = ["serde", "dep:postcard"]
+## Enable the COCKTAIL-DKG distributed key generation protocol.
+cocktail-dkg = []
 # Exposes ciphersuite-generic tests for other crates to use
 test-impl = ["dep:proptest", "dep:serde_json", "dep:criterion", "dep:tokio", "dep:debugless-unwrap"]
 

frost-core/src/error.rs

@@ -90,6 +90,24 @@ pub enum Error<C: Ciphersuite> {
         /// The identifier of the signer whose share validation failed.
         culprit: Identifier<C>,
     },
+    /// Decryption of an encrypted share failed.
+    #[cfg(feature = "cocktail-dkg")]
+    #[error("Decryption of an encrypted share failed.")]
+    DecryptionFailed {
+        /// The identifier of the participant who sent the invalid ciphertext.
+        culprit: Identifier<C>,
+    },
+    /// A transcript signature is not valid.
+    #[cfg(feature = "cocktail-dkg")]
+    #[error("Invalid transcript signature.")]
+    InvalidTranscriptSignature {
+        /// The identifier of the participant whose transcript signature was invalid.
+        culprit: Identifier<C>,
+    },
+    /// Duplicated static public keys were provided.
+    #[cfg(feature = "cocktail-dkg")]
+    #[error("Duplicated static public keys provided.")]
+    DuplicatedVerifyingKeys,
     /// Error in scalar Field.
     #[error("Error in scalar Field.")]
     FieldError(#[from] FieldError),
@@ -126,6 +144,12 @@ where
             Error::InvalidSignatureShare { culprits } => culprits.clone(),
             Error::InvalidProofOfKnowledge { culprit } => vec![*culprit],
             Error::InvalidSecretShare { culprit } => culprit.map(|i| vec![i]).unwrap_or_default(),
+            #[cfg(feature = "cocktail-dkg")]
+            Error::DecryptionFailed { culprit } => vec![*culprit],
+            #[cfg(feature = "cocktail-dkg")]
+            Error::InvalidTranscriptSignature { culprit } => vec![*culprit],
+            #[cfg(feature = "cocktail-dkg")]
+            Error::DuplicatedVerifyingKeys => vec![],
             Error::InvalidMinSigners
             | Error::InvalidMaxSigners
             | Error::InvalidCoefficients

frost-core/src/keys.rs

@@ -30,6 +30,9 @@ use crate::serialization::{Deserialize, Serialize};
 
 use super::compute_lagrange_coefficient;
 
+#[cfg(feature = "cocktail-dkg")]
+#[cfg_attr(docsrs, doc(cfg(feature = "cocktail-dkg")))]
+pub mod cocktail_dkg;
 pub mod dkg;
 pub mod refresh;
 pub mod repairable;