feat/lamport plus

.github/workflows/rust.yml

@@ -34,14 +34,14 @@ jobs:
         run: cargo test --verbose --all-features
 
   msrv:
-    name: Verify MSRV (1.87)
+    name: Verify MSRV (1.96)
     runs-on: ubuntu-latest
 
     steps:
       - uses: actions/checkout@v4
 
-      - name: Install Rust Toolchain (1.87)
-        uses: dtolnay/rust-toolchain@1.87.0
+      - name: Install Rust Toolchain (1.96)
+        uses: dtolnay/rust-toolchain@1.96.0
 
       - name: Check
         run: cargo check --all-features

CHANGELOG.md

@@ -5,6 +5,21 @@ All notable changes to this project are documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 This project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [1.3.0] - 2026-09-01
+
+### Added
+
+- Merkle-tree Lamport multisig view (`views::lamport_merkle`, behind the default `lamport` feature) wrapping the `lamport_signature_plus` 0.5.0 `Mt*` API: signature-share accumulation in `ThresholdData` and combination via `MtSignature::combine`, for 11 digest variants (SHA3-512/384/256, SHA2-512/384/256, BLAKE2b-512, BLAKE2s-256, BLAKE3-256, SHAKE-128/256) with the 22 new `LamportMerkle*Sig`/`*SigShare` codecs (codes `0x1a94`-`0x1aae`).
+- `AttrId::Depth` attribute (code 11, name `depth`, one raw byte) for merkle-tree signature schemes, stamped on accumulators and combined signatures and cross-checked against the depth byte embedded in the share blobs; mismatches return `AttributesError::DepthMismatch`.
+- `Builder::with_depth(depth)` and `Multisig::depth() -> Option<u8>`.
+- The 11 `LamportMerkle*Sig` codecs added to `SIG_CODECS` (35→46 entries without the XMSS duplicate fix, 47 entries total) and the 11 `LamportMerkle*SigShare` codecs added to `SIG_SHARE_CODECS` (2→13).
+
+### Changed
+
+- Bumped `lamport_signature_plus` from `0.5.0-rc2` to `0.5.0`.
+- Raised `rust-version` from `1.87` to `1.96` (required by `lamport_signature_plus` 0.5.0).
+- `multi-codec` dependency raised to `1.3` (adds the `LamportMerkle*` codecs).
+
 ## [1.2.1] - 2026-08-18
 
 ### Fixed

Cargo.toml

@@ -1,8 +1,8 @@
 [package]
 name = "multi-sig"
-version = "1.2.1"
+version = "1.3.0"
 edition = "2024"
-rust-version = "1.87"
+rust-version = "1.96"
 authors = ["Dave Grantham <dwg@linuxprogrammer.org>"]
 description = "Multisig self-describing multicodec implementation for digital signatures"
 repository = "https://github.com/cryptidtech/multi-sig.git"
@@ -21,14 +21,15 @@ serde = []
 lamport = ["dep:lamport_signature_plus", "dep:sha3", "dep:sha2", "dep:blake2", "dep:shake", "dep:blake3"]
 xmss = ["dep:xmss"]
 
+# Local multi-codec 1.3.0 until it is published (remove at release).
 [dependencies]
 ciborium = "0.2"
 chacha20poly1305 = "0.11"
 elliptic-curve = "0.14"
 getrandom = { version = "0.4" }
 # blsful configured per-target below (blst for native, rust for wasm)
 multi-base = { version = "1.0", default-features = false }
-multi-codec = "1.2"
+multi-codec = "1.3"
 multi-trait = { version = "1.0", default-features = false }
 multi-util = "1.1"
 serde = { version = "1.0", default-features = false, features = ["alloc", "derive"] }
@@ -37,7 +38,7 @@ thiserror = { version = "2.0" }
 unsigned-varint = { version = "0.8", features = ["std"] }
 zeroize = "1"
 # Lamport support (feature-gated, default-enabled)
-lamport_signature_plus = { version = "0.5.0-rc2", optional = true }
+lamport_signature_plus = { version = "0.5.0", optional = true }
 sha3 = { version = "0.12", optional = true }
 sha2 = { version = "0.11", optional = true }
 blake2 = { version = "0.11.0-rc.6", optional = true }
@@ -59,6 +60,7 @@ ssh-key = { version = "0.7.0-rc.11", default-features = false, features = ["allo
 criterion = { version = "0.8", features = ["html_reports"] }
 hex = "0.4"
 proptest = "1.11"
+rand = "0.10"
 serde_json = "1.0"
 serde_test = "1.0"
 
@@ -75,3 +77,7 @@ multiple_crate_versions = { level = "allow", priority = 1 }
 
 [lints.rust]
 unsafe_code = "deny"
+
+# Local multi-codec 1.3.0 until it is published (remove at release).
+[patch.crates-io]
+multi-codec = { path = "../multi-codec" }

src/attrid.rs

@@ -31,6 +31,10 @@ pub enum AttrId {
     ThresholdMetaCipher,
     /// XMSS leaf index (u32 big-endian) for stateful signature schemes.
     SigIndex,
+    /// Merkle-tree signature scheme depth (one raw byte; the tree holds
+    /// 2^depth one-time leaves). Cross-checked against the depth byte embedded
+    /// in the signature wire data.
+    Depth,
 }
 
 impl AttrId {
@@ -53,6 +57,7 @@ impl AttrId {
             Self::EncryptedThresholdMeta => "encrypted-threshold-meta",
             Self::ThresholdMetaCipher => "threshold-meta-cipher",
             Self::SigIndex => "sig-index",
+            Self::Depth => "depth",
         }
     }
 }
@@ -79,6 +84,7 @@ impl TryFrom<u8> for AttrId {
             8 => Ok(Self::EncryptedThresholdMeta),
             9 => Ok(Self::ThresholdMetaCipher),
             10 => Ok(Self::SigIndex),
+            11 => Ok(Self::Depth),
             _ => Err(AttributesError::InvalidAttributeValue(c).into()),
         }
     }
@@ -124,6 +130,7 @@ impl TryFrom<&str> for AttrId {
             "encrypted-threshold-meta" => Ok(Self::EncryptedThresholdMeta),
             "threshold-meta-cipher" => Ok(Self::ThresholdMetaCipher),
             "sig-index" => Ok(Self::SigIndex),
+            "depth" => Ok(Self::Depth),
             _ => Err(AttributesError::InvalidAttributeName(s.to_string()).into()),
         }
     }

src/error.rs

@@ -108,6 +108,15 @@ pub enum AttributesError {
     /// Invalid attribute value
     #[error("Invalid attribute value {0}")]
     InvalidAttributeValue(u8),
+    /// A merkle-tree depth attribute does not match the depth byte embedded in
+    /// the signature wire data.
+    #[error("Depth mismatch: attribute says {expected}, wire data says {found}")]
+    DepthMismatch {
+        /// depth declared by the `depth` attribute
+        expected: u8,
+        /// depth byte embedded in the wire data
+        found: u8,
+    },
 }
 
 /// Shares errors created by this library

src/lib.rs

@@ -154,6 +154,10 @@ pub use views::{
     ThresholdView, Views, decrypt_threshold_meta, encrypt_threshold_meta, generate_meta_key,
 };
 
+/// Merkle-tree Lamport signature view
+#[cfg(feature = "lamport")]
+pub use views::lamport_merkle;
+
 /// Serde serialization
 #[cfg(feature = "serde")]
 pub mod serde;