refactor(forks/lstar): type SignedBlock.proof and rename multi-signature types

packages/testing/src/consensus_testing/keys.py

@@ -65,7 +65,7 @@
 from lean_spec.spec.forks.lstar.containers import (
     AggregatedAttestations,
     AttestationData,
-    TypeOneMultiSignature,
+    SingleMessageAggregate,
 )
 from lean_spec.spec.ssz import Bytes32, Uint64
 
@@ -513,21 +513,24 @@ def sign_and_aggregate(
         self,
         validator_ids: list[ValidatorIndex],
         attestation_data: AttestationData,
-    ) -> TypeOneMultiSignature:
+    ) -> SingleMessageAggregate:
         """
-        Sign attestation data with each validator and aggregate into a Type-1 proof.
+        Sign attestation data with each validator and aggregate the result.
+
+        Returns a single-message aggregate proof binding all participants
+        to the (data, slot) pair.
 
         Each validator's XMSS attestation key signs the attestation data
         root. The signatures are then handed to the multi-signature
-        binding to produce a single cryptographically valid Type-1 proof
+        binding to produce a single cryptographically valid single-message aggregate proof
         binding all participants to (data, slot).
 
         Args:
             validator_ids: Validators to sign with.
             attestation_data: The attestation data to sign.
 
         Returns:
-            Cryptographically valid Type-1 proof covering validator_ids.
+            Cryptographically valid single-message aggregate proof covering validator_ids.
         """
         raw_xmss = [
             (
@@ -537,7 +540,7 @@ def sign_and_aggregate(
             )
             for vid in validator_ids
         ]
-        return TypeOneMultiSignature.aggregate(
+        return SingleMessageAggregate.aggregate(
             children=[],
             raw_xmss=raw_xmss,
             message=hash_tree_root(attestation_data),
@@ -549,15 +552,15 @@ def build_attestation_proofs(
         aggregated_attestations: AggregatedAttestations,
         signature_lookup: Mapping[AttestationData, Mapping[ValidatorIndex, Signature]]
         | None = None,
-    ) -> list[TypeOneMultiSignature]:
+    ) -> list[SingleMessageAggregate]:
         """
-        Produce Type-1 proofs aligned with the given attestations.
+        Produce single-message aggregate proofs aligned with the given attestations.
 
         For each aggregated attestation:
 
         1. Identify participating validators from the aggregation bitfield.
         2. Collect each participant's attestation public key and signature.
-        3. Combine them into a single Type-1 single-message proof via the
+        3. Combine them into a single single-message aggregate single-message proof via the
            multi-signature binding.
 
         Pre-computed signatures can be supplied via the lookup to avoid
@@ -569,11 +572,11 @@ def build_attestation_proofs(
                 attestation data then validator index.
 
         Returns:
-            One Type-1 single-message proof per attestation, parallel to the input.
+            One single-message aggregate proof per attestation, parallel to the input.
         """
         lookup = signature_lookup or {}
 
-        proofs: list[TypeOneMultiSignature] = []
+        proofs: list[SingleMessageAggregate] = []
         for agg in aggregated_attestations:
             # Decode which validators participated from the bitfield.
             validator_ids = agg.aggregation_bits.to_validator_indices()
@@ -594,7 +597,7 @@ def build_attestation_proofs(
             # Produce a single aggregated proof that the leanVM can verify
             # in one pass over all participants.
             proofs.append(
-                TypeOneMultiSignature.aggregate(
+                SingleMessageAggregate.aggregate(
                     children=[],
                     raw_xmss=list(zip(validator_ids, public_keys, signatures, strict=True)),
                     message=hash_tree_root(agg.data),

packages/testing/src/consensus_testing/test_fixtures/state_transition.py

@@ -12,8 +12,8 @@
     AttestationData,
     Block,
     BlockBody,
+    SingleMessageAggregate,
     State,
-    TypeOneMultiSignature,
 )
 from lean_spec.spec.forks.lstar.spec import LstarSpec
 from lean_spec.spec.ssz import Bytes32
@@ -255,7 +255,7 @@ def _build_block_from_spec(
 
         # Path 3: normal block construction via the spec's builder.
         else:
-            aggregated_payloads: dict[AttestationData, set[TypeOneMultiSignature]] = {}
+            aggregated_payloads: dict[AttestationData, set[SingleMessageAggregate]] = {}
             if spec.attestations:
                 aggregated_payloads = StateTransitionTest._build_aggregated_payloads_from_spec(
                     spec.attestations, state, block_registry
@@ -301,7 +301,7 @@ def _build_aggregated_payloads_from_spec(
         attestation_specs: list[AggregatedAttestationSpec],
         state: State,
         block_registry: dict[str, Block],
-    ) -> dict[AttestationData, set[TypeOneMultiSignature]]:
+    ) -> dict[AttestationData, set[SingleMessageAggregate]]:
         """
         Build aggregated signature payloads from attestation specifications.
 
@@ -317,7 +317,7 @@ def _build_aggregated_payloads_from_spec(
         # XMSS keys require precomputation up to the highest slot used.
         max_slot = max(spec.slot for spec in attestation_specs)
         key_manager = XmssKeyManager.shared(max_slot=max_slot)
-        payloads: dict[AttestationData, set[TypeOneMultiSignature]] = {}
+        payloads: dict[AttestationData, set[SingleMessageAggregate]] = {}
 
         for spec in attestation_specs:
             if not spec.valid_signature:

packages/testing/src/consensus_testing/test_fixtures/verify_signatures.py

@@ -11,6 +11,7 @@
     AggregatedAttestation,
     AggregatedAttestations,
     AttestationData,
+    MultiMessageAggregate,
     SignedBlock,
     State,
 )
@@ -68,7 +69,7 @@ class VerifySignaturesTest(BaseConsensusFixture):
       set bit. Exercises the empty-participants check inside
       signature verification.
     - `{"operation": "corrupt_proof"}`: Replace the merged proof with
-      a short non-decodable blob. Exercises the Type-2 decode check.
+      a short non-decodable blob. Exercises the multi-message aggregate decode check.
     - `{"operation": "append_phantom_attestation"}`: Add a body
       attestation with no matching proof component. Exercises the
       component count check between the body and the merged proof.
@@ -177,9 +178,11 @@ def _apply_tamper(self, signed_block: SignedBlock) -> SignedBlock:
             return signed_block
 
         if operation == "corrupt_proof":
-            # Replace the merged proof with a short non-decodable blob.
-            # Decoding the Type-2 envelope must fail before verification.
-            signed_block.proof = ByteList512KiB(data=b"\x00\x01\x02\x03")
+            # Replace the merged proof with a short bogus payload.
+            # The verifier rejects the malformed proof bytes.
+            signed_block.proof = MultiMessageAggregate(
+                proof=ByteList512KiB(data=b"\x00\x01\x02\x03"),
+            )
             return signed_block
 
         if operation == "append_phantom_attestation":

packages/testing/src/consensus_testing/test_types/aggregated_attestation_spec.py

@@ -9,8 +9,8 @@
     AggregatedAttestations,
     AttestationData,
     Block,
+    SingleMessageAggregate,
     State,
-    TypeOneMultiSignature,
 )
 from lean_spec.spec.ssz import ByteList512KiB, Bytes32
 
@@ -161,7 +161,7 @@ def build_invalid_proof(
         state: State,
         key_manager: XmssKeyManager,
         block: Block,
-    ) -> tuple[Block, TypeOneMultiSignature]:
+    ) -> tuple[Block, SingleMessageAggregate]:
         """
         Build an invalid attestation proof and append it to the block body.
 
@@ -187,20 +187,20 @@ def build_invalid_proof(
             data=attestation_data,
         )
 
-        # Empty proof bytes flag "no real Type-1 here" — the caller treats
+        # Empty proof bytes flag "no real single-message aggregate here" — the caller treats
         # any such entry as a placeholder and bypasses real binding merges.
         placeholder = ByteList512KiB(data=b"")
 
         if not self.valid_signature:
-            invalid_proof = TypeOneMultiSignature(participants=aggregation_bits, proof=placeholder)
+            invalid_proof = SingleMessageAggregate(participants=aggregation_bits, proof=placeholder)
         elif self.signer_ids is not None:
             # Valid proof from wrong validators (participant mismatch).
             valid_proof = key_manager.sign_and_aggregate(self.signer_ids, attestation_data)
-            invalid_proof = TypeOneMultiSignature(
+            invalid_proof = SingleMessageAggregate(
                 participants=aggregation_bits, proof=valid_proof.proof
             )
         else:
-            invalid_proof = TypeOneMultiSignature(participants=aggregation_bits, proof=placeholder)
+            invalid_proof = SingleMessageAggregate(participants=aggregation_bits, proof=placeholder)
 
         # Append invalid attestation to the block body.
         block.body.attestations = AggregatedAttestations(

packages/testing/src/consensus_testing/test_types/block_spec.py

@@ -17,11 +17,11 @@
     AttestationData,
     Block,
     BlockBody,
+    MultiMessageAggregate,
     SignedAttestation,
     SignedBlock,
+    SingleMessageAggregate,
     State,
-    TypeOneMultiSignature,
-    TypeTwoMultiSignature,
 )
 from lean_spec.spec.forks.lstar.spec import LstarSpec
 from lean_spec.spec.forks.lstar.store import Store
@@ -239,29 +239,30 @@ def build_attestations(
     def _sign_block(
         self,
         final_block: Block,
-        attestation_proofs: list[TypeOneMultiSignature],
+        attestation_proofs: list[SingleMessageAggregate],
         proposer_index: ValidatorIndex,
         key_manager: XmssKeyManager,
         state: State,
     ) -> SignedBlock:
         """Sign a block and assemble the final SignedBlock with the merged proof.
 
-        Builds a Type-1 wrapping the proposer's XMSS signature, then merges
-        that with the per-attestation Type-1 proofs into a single Type-2 proof
-        and SSZ-encodes it onto the envelope. Consumers of this filler feed
-        the block through spec.on_block / verify_signatures, which decodes
-        the proof and verifies it, so an honest merged proof is required.
+        Builds a single-message aggregate wrapping the proposer's XMSS
+        signature, then merges that with the per-attestation single-message
+        aggregate proofs into a single multi-message aggregate proof and
+        stores it on the envelope. Consumers of this filler feed the block
+        through spec.on_block / verify_signatures, which decodes the proof
+        and verifies it, so an honest merged proof is required.
 
         When valid_signature is False, the proposer signature is a dummy
         XMSS one and the binding-driven aggregation would reject it before
-        verify_signatures ever runs. The Type-2 envelope is then assembled
+        verify_signatures ever runs. The multi-message aggregate envelope is then assembled
         directly from the info entries with empty proof bytes — that
         decodes structurally and lets verify_signatures reach (and reject
         at) the verify_type_2 call, which is the contract the test exercises.
 
         Args:
             final_block: The unsigned block.
-            attestation_proofs: Per-attestation Type-1 proofs (parallel to
+            attestation_proofs: Per-attestation single-message aggregate proofs (parallel to
                 final_block.body.attestations).
             proposer_index: Which validator proposes this block.
             key_manager: XMSS key manager for signing.
@@ -277,7 +278,7 @@ def _sign_block(
         # The binding rejects placeholder bytes; if anything in the merged
         # input is a dummy (invalid proposer sig or a build_invalid_proof
         # attestation), bypass aggregate_type_2 entirely and assemble the
-        # Type-2 envelope by hand. The result still SSZ-decodes so
+        # multi-message aggregate envelope by hand. The result still SSZ-decodes so
         # verify_signatures reaches verify_type_2 for the rejection.
         any_placeholder_attestation = any(not proof.proof.data for proof in attestation_proofs)
         use_placeholder = not self.valid_signature or any_placeholder_attestation
@@ -288,7 +289,7 @@ def _sign_block(
                 self.slot,
                 block_root,
             )
-            proposer_type_1 = TypeOneMultiSignature.aggregate(
+            proposer_single_message_aggregate = SingleMessageAggregate.aggregate(
                 children=[],
                 raw_xmss=[(proposer_index, proposer_pubkey, proposer_signature)],
                 message=block_root,
@@ -304,19 +305,16 @@ def _sign_block(
             ]
             public_keys_per_part.append([proposer_pubkey])
 
-            merged = TypeTwoMultiSignature.aggregate(
-                [*attestation_proofs, proposer_type_1],
+            proof = MultiMessageAggregate.aggregate(
+                [*attestation_proofs, proposer_single_message_aggregate],
                 public_keys_per_part=public_keys_per_part,
             )
-            proof_bytes = merged.encode_bytes()
         else:
-            placeholder = ByteList512KiB(data=b"")
-            envelope = TypeTwoMultiSignature(proof=placeholder)
-            proof_bytes = envelope.encode_bytes()
+            proof = MultiMessageAggregate(proof=ByteList512KiB(data=b""))
 
         return SignedBlock(
             block=final_block,
-            proof=ByteList512KiB(data=proof_bytes),
+            proof=proof,
         )
 
     def build_signed_block(
@@ -436,11 +434,11 @@ def build_signed_block_with_store(
         Simulates what a real node does when proposing a block.
         Replays the gossip, aggregation, and proposal pipeline through the Store.
 
-        Returns a Store enriched with the aggregated Type-1 payloads built
+        Returns a Store enriched with the aggregated single-message aggregate payloads built
         during the simulated pipeline. The caller can persist these so future
         block builds can re-aggregate the same attestations rather than
         reconstructing them from on-chain block bodies (which would require
-        splitting the block-level Type-2 proof — a heavy and, in the test
+        splitting the block-level multi-message aggregate proof — a heavy and, in the test
         recursive-aggregation mode, unreliable operation). Other fields of
         the original Store (gossip signatures, time, head, etc.) are
         preserved so the simulated build does not consume state the caller
@@ -471,7 +469,7 @@ def build_signed_block_with_store(
 
         # Preserve the caller's Store so unrelated fields (gossip signatures,
         # head, finalization checkpoints, time) survive the simulated pipeline.
-        # Only the freshly aggregated Type-1 payloads merge back at the end.
+        # Only the freshly aggregated single-message aggregate payloads merge back at the end.
         caller_store = store
         store = copy.deepcopy(store)
 
@@ -512,7 +510,7 @@ def build_signed_block_with_store(
         # Trigger Store aggregation to merge gossip signatures into known payloads.
         # Aggregation runs on a local clone: gossip pools mutate here, but the
         # caller's gossip-signature view must not be consumed by this simulated
-        # build. Only the freshly aggregated Type-1 payloads propagate back.
+        # build. Only the freshly aggregated single-message aggregate payloads propagate back.
         aggregation_store, _ = spec.aggregate(store)
         merged_store = spec.accept_new_attestations(aggregation_store)
 

packages/testing/src/consensus_testing/test_types/gossip_aggregated_attestation_spec.py

@@ -8,8 +8,8 @@
     AttestationData,
     Block,
     SignedAggregatedAttestation,
+    SingleMessageAggregate,
     State,
-    TypeOneMultiSignature,
 )
 from lean_spec.spec.ssz import ByteList512KiB, Bytes32
 
@@ -185,7 +185,7 @@ def build_signed(
         # Exercises signature verification rejection.
         if not self.valid_signature:
             placeholder = ByteList512KiB(data=b"\x00" * 32)
-            proof = TypeOneMultiSignature(
+            proof = SingleMessageAggregate(
                 participants=ValidatorIndices(data=validator_ids).to_aggregation_bits(),
                 proof=placeholder,
             )
@@ -202,7 +202,7 @@ def build_signed(
         # but the claimed participants no longer match.
         # The store must detect and reject this inconsistency.
         if self.signer_ids and self.signer_ids != self.validator_ids:
-            proof = TypeOneMultiSignature(
+            proof = SingleMessageAggregate(
                 participants=ValidatorIndices(data=validator_ids).to_aggregation_bits(),
                 proof=proof.proof,
             )