feat(runtime)!: import the Groth16 host function so proofs verify natively; nodes older than 0.4.0 cannot import spec 19 (zk-verifier 3.3.0, pallet-zk-verifier 0.18.0)

.github/workflows/test.yml

@@ -75,12 +75,14 @@ jobs:
       - name: Check workspace
         run: cargo check --release --workspace
 
-      # zk-core must build in a no_std/WASM context. Guard against a consumer or
-      # feature change that leaks `std` into the runtime build.
-      - name: Check zk-core no_std feature matrix
+      # zk-core and zk-verifier must build in a no_std/WASM context. Guard against
+      # a consumer or feature change that leaks `std` into the runtime build.
+      - name: Check zk primitives no_std feature matrix
         run: |
           cargo check -p orbinum-zk-core --no-default-features
           cargo check -p orbinum-zk-core --no-default-features --features poseidon-native
+          cargo check -p orbinum-zk-verifier --no-default-features
+          cargo check -p orbinum-zk-verifier --no-default-features --features groth16-native
 
   # Step 3: Build workspace - compiles once for all subsequent jobs to reuse
   build:

frame/zk-verifier/CHANGELOG.md

@@ -6,6 +6,14 @@ All notable changes to this pallet are documented here.
 
 ## [Unreleased]
 
+## [0.18.0] - 2026-10-13
+
+### Added
+
+- Feature `groth16-native`: the pairing runs through the node's
+  `bn254_groth16_verify` host function instead of in Wasm. Same function, same
+  results; off by default.
+
 ## [0.17.1] - 2026-10-09
 
 ### Changed

frame/zk-verifier/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "pallet-zk-verifier"
-version = "0.17.1"
+version = "0.18.0"
 description = "Zero-Knowledge proof verification pallet for Orbinum"
 authors = ["Orbinum Team"]
 license = "GPL-3.0-or-later"
@@ -74,6 +74,7 @@ runtime-benchmarks = [
 	"dep:ark-groth16",
 ]
 skip-proof-verification = []
+groth16-native = ["orbinum-zk-verifier/groth16-native"]
 try-runtime = [
 	"frame-support/try-runtime",
 	"frame-system/try-runtime",

frame/zk-verifier/src/verifier.rs

@@ -130,8 +130,9 @@ fn record_stats<T: Config>(circuit_id: CircuitId, version: u32, result: bool) {
 	});
 }
 
-/// The pairing, under a key in prepared form: [`verify_prepared`], the same
-/// function the node's `bn254_groth16_verify` host function runs.
+/// The pairing, under a key in prepared form: [`verify_prepared`], natively
+/// through the node's `bn254_groth16_verify` host function under
+/// `groth16-native`, in Wasm otherwise.
 ///
 /// Always `true` in **test** builds, whose keys deserialize but carry no real
 /// proofs. Benchmarks run the full pairing, so weights include it.
@@ -144,7 +145,16 @@ fn do_verify(prepared: &[u8], proof: &[u8], inputs: &[[u8; 32]]) -> bool {
 		true
 	}
 
-	#[cfg(not(test))]
+	#[cfg(all(not(test), feature = "groth16-native"))]
+	{
+		orbinum_zk_verifier::host_interface::groth_16_host_interface::bn254_groth16_verify(
+			prepared,
+			proof,
+			&inputs.concat(),
+		)
+	}
+
+	#[cfg(all(not(test), not(feature = "groth16-native")))]
 	{
 		orbinum_zk_verifier::verify_prepared(prepared, proof, &inputs.concat())
 	}

primitives/zk-verifier/CHANGELOG.md

@@ -6,6 +6,14 @@ All notable changes to this crate are documented here.
 
 ## [Unreleased]
 
+## [3.3.0] - 2026-10-13
+
+### Changed
+
+- `bn254_groth16_verify` drops `register_only` (`#[version(1)]`): runtimes can
+  import it. Symbol and behaviour unchanged; nodes from 0.4.0 already register
+  it.
+
 ## [3.2.0] - 2026-10-09
 
 ### Added

primitives/zk-verifier/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "orbinum-zk-verifier"
-version = "3.2.0"
+version = "3.3.0"
 authors = ["Orbinum Network <contact@orbinum.net>"]
 edition = "2021"
 publish = false

primitives/zk-verifier/src/host_interface.rs

@@ -3,10 +3,8 @@
 //!
 //! - **Frozen.** Executed blocks call version 1 and syncing nodes re-run them:
 //!   any observable change is a new `#[version(N)]`, and version 1 stays.
-//! - **`register_only`.** A node without the function cannot instantiate a
-//!   runtime that imports it, so nodes register it first and no runtime calls
-//!   it yet. A later runtime drops the flag once every node runs a release
-//!   with it (minimum author version for authors; RPC and archive by hand).
+//! - **Imported from spec 19.** Registered `register_only` since node 0.4.0;
+//!   a node without it cannot instantiate a runtime that imports it.
 
 use alloc::vec::Vec;
 use sp_runtime_interface::{pass_by::PassFatPointerAndRead, runtime_interface};
@@ -16,7 +14,7 @@ use sp_runtime_interface::{pass_by::PassFatPointerAndRead, runtime_interface};
 pub trait Groth16HostInterface {
 	/// [`crate::verify_prepared`], natively. It must never panic: natively a
 	/// panic takes the node down instead of trapping the runtime.
-	#[version(1, register_only)]
+	#[version(1)]
 	fn bn254_groth16_verify(
 		prepared_vk: PassFatPointerAndRead<&[u8]>,
 		proof: PassFatPointerAndRead<&[u8]>,

template/runtime/Cargo.toml

@@ -102,7 +102,7 @@ sp-maybe-compressed-blob = "11.1.0"
 grandpa-verifier-primitives = { workspace = true, features = ["std"] }
 
 [features]
-default = ["std", "with-rocksdb-weights", "poseidon-native-runtime"]
+default = ["std", "with-rocksdb-weights", "poseidon-native-runtime", "groth16-native-runtime"]
 with-rocksdb-weights = []
 with-paritydb-weights = []
 
@@ -116,6 +116,9 @@ hyperbridge-testnet = []
 poseidon-native-runtime = [
 	"pallet-shielded-pool/poseidon-native",
 ]
+groth16-native-runtime = [
+	"pallet-zk-verifier/groth16-native",
+]
 
 std = [
 	"ethereum/std",

template/runtime/RUNTIME_VERSIONS.md

@@ -28,7 +28,8 @@ every EVM priority tip goes to the validator that authored the block.
 `transaction_version` moves: pallet index 16 and `shielded_pool` call 18 are
 gone, and call 19 is renamed. Ships with `orbinum-runtime` / `orbinum-node`
 0.5.0, `pallet-shielded-pool` 0.25.0, `pallet-shielded-pool-runtime-api` 0.4.0,
-`pallet-evm-precompile-shielded-pool` 0.10.0 and `pallet-validator-set` 0.4.1.
+`pallet-evm-precompile-shielded-pool` 0.10.0, `pallet-validator-set` 0.4.1,
+`pallet-zk-verifier` 0.18.0 and `orbinum-zk-verifier` 3.3.0.
 
 #### 1 · Block author is the session validator
 
@@ -61,6 +62,15 @@ A transaction's priority tip goes to the block author's validator account
 (`TipToValidator`); `block.coinbase` is the zero address. It used to be bytes
 4..24 of the Aura key, whose mapped account no key controls.
 
+#### 4 · Groth16 host function
+
+The runtime imports `bn254_groth16_verify` (`groth16-native-runtime`): proof
+verification runs natively instead of in Wasm (`verify_proof` 2.43 → 0.61 ms).
+Same function on both paths, so results do not change. Nodes register it since
+0.4.0; an older node cannot instantiate this runtime and stops importing, so
+every node (validators, RPC, archive) must run ≥ 0.4.0 before `setCode`.
+Weights are unchanged (measured in Wasm, so they overcharge).
+
 #### Migrations
 
 - `RelayerFeesToPool` — drains `Relayer::PendingRelayerFees` into

template/runtime/build.rs

@@ -6,11 +6,13 @@ fn main() {
 			.export_heap_base()
 			.import_memory();
 
-		// Poseidon via host functions (~3× faster). Skipped for try-runtime
-		// builds: the stock try-runtime CLI executor lacks the custom host
-		// interface, so those builds fall back to the pure-wasm hasher.
+		// Poseidon (~3×) and Groth16 (~3.5×) via host functions. Skipped for
+		// try-runtime builds: the stock try-runtime CLI executor lacks the
+		// custom host interfaces, so those builds fall back to pure Wasm.
 		if std::env::var("CARGO_FEATURE_TRY_RUNTIME").is_err() {
-			builder = builder.enable_feature("poseidon-native-runtime");
+			builder = builder
+				.enable_feature("poseidon-native-runtime")
+				.enable_feature("groth16-native-runtime");
 		}
 
 		builder.enable_metadata_hash("ORB", 18).build();

template/runtime/src/runtime_tests.rs

@@ -588,21 +588,18 @@ fn signed_extra_implicit_succeeds_with_check_metadata_hash() {
 
 // ── Host functions ────────────────────────────────────────────────────────────
 
-/// The runtime must not import `bn254_groth16_verify` before every node
-/// registers it: a node without it cannot instantiate the runtime and stops
-/// importing. Flip when a runtime turns it on.
+/// Spec 19 imports `bn254_groth16_verify`, registered since node 0.4.0. A
+/// node without it cannot instantiate the runtime and stops importing.
 #[test]
-fn the_runtime_does_not_import_the_groth16_host_function_yet() {
+fn the_runtime_imports_the_groth16_host_function() {
 	let Some(blob) = crate::WASM_BINARY else {
 		return; // SKIP_WASM_BUILD
 	};
 	// Release builds embed the compressed blob.
 	let wasm = sp_maybe_compressed_blob::decompress(blob, 64 << 20).expect("runtime blob");
 	let imports = |symbol: &[u8]| wasm.windows(symbol.len()).any(|w| w == symbol);
-	// The search works: Poseidon's host function is imported.
-	assert!(imports(b"ext_poseidon_host_interface_poseidon_hash_2"));
-	assert!(!imports(
-		b"ext_groth_16_host_interface_bn254_groth16_verify"
+	assert!(imports(
+		b"ext_groth_16_host_interface_bn254_groth16_verify_version_1"
 	));
 }