diff --git a/packages/testing/src/consensus_testing/keys.py b/packages/testing/src/consensus_testing/keys.py
index 556efe87..4819408e 100755
--- a/packages/testing/src/consensus_testing/keys.py
+++ b/packages/testing/src/consensus_testing/keys.py
@@ -44,8 +44,10 @@
     AttestationSignatures,
 )
 from lean_spec.subspecs.containers.slot import Slot
-from lean_spec.subspecs.containers.state.types import AttestationSignatureKey
-from lean_spec.subspecs.xmss.aggregation import MultisigAggregatedSignature
+from lean_spec.subspecs.xmss.aggregation import (
+    AttestationSignatureKey,
+    MultisigAggregatedSignature,
+)
 from lean_spec.subspecs.xmss.containers import KeyPair, PublicKey, Signature
 from lean_spec.subspecs.xmss.interface import (
     PROD_SIGNATURE_SCHEME,
diff --git a/packages/testing/src/consensus_testing/test_fixtures/fork_choice.py b/packages/testing/src/consensus_testing/test_fixtures/fork_choice.py
index 38e30a07..3f62bec1 100644
--- a/packages/testing/src/consensus_testing/test_fixtures/fork_choice.py
+++ b/packages/testing/src/consensus_testing/test_fixtures/fork_choice.py
@@ -26,10 +26,10 @@
 from lean_spec.subspecs.containers.slot import Slot
 from lean_spec.subspecs.containers.state import Validators
 from lean_spec.subspecs.containers.state.state import State
-from lean_spec.subspecs.containers.state.types import AttestationSignatureKey
 from lean_spec.subspecs.forkchoice import Store
 from lean_spec.subspecs.koalabear import Fp
 from lean_spec.subspecs.ssz import hash_tree_root
+from lean_spec.subspecs.xmss.aggregation import AttestationSignatureKey
 from lean_spec.subspecs.xmss.containers import Signature
 from lean_spec.subspecs.xmss.types import HashDigestList, HashTreeOpening, Randomness
 from lean_spec.types import Bytes32, Uint64
diff --git a/src/lean_spec/subspecs/containers/__init__.py b/src/lean_spec/subspecs/containers/__init__.py
index 0cf54111..33ce84af 100644
--- a/src/lean_spec/subspecs/containers/__init__.py
+++ b/src/lean_spec/subspecs/containers/__init__.py
@@ -13,8 +13,7 @@
     AggregationBits,
     Attestation,
     AttestationData,
-    NaiveAggregatedSignature,
-    SignedAggregatedAttestation,
+    AttestationsByValidator,
     SignedAttestation,
 )
 from .block import (
@@ -31,19 +30,18 @@
 
 __all__ = [
     "AggregatedAttestation",
-    "NaiveAggregatedSignature",
     "AggregationBits",
-    "AttestationData",
     "Attestation",
-    "SignedAttestation",
-    "SignedAggregatedAttestation",
+    "AttestationData",
+    "AttestationsByValidator",
     "Block",
-    "BlockWithAttestation",
     "BlockBody",
     "BlockHeader",
+    "BlockWithAttestation",
     "Checkpoint",
     "Config",
+    "SignedAttestation",
     "SignedBlockWithAttestation",
-    "Validator",
     "State",
+    "Validator",
 ]
diff --git a/src/lean_spec/subspecs/containers/attestation/__init__.py b/src/lean_spec/subspecs/containers/attestation/__init__.py
index 7e05a530..615d2f4d 100644
--- a/src/lean_spec/subspecs/containers/attestation/__init__.py
+++ b/src/lean_spec/subspecs/containers/attestation/__init__.py
@@ -4,17 +4,15 @@
     AggregatedAttestation,
     Attestation,
     AttestationData,
-    SignedAggregatedAttestation,
     SignedAttestation,
 )
-from .types import AggregationBits, NaiveAggregatedSignature
+from .types import AggregationBits, AttestationsByValidator
 
 __all__ = [
-    "AttestationData",
-    "Attestation",
-    "SignedAttestation",
-    "SignedAggregatedAttestation",
     "AggregatedAttestation",
-    "NaiveAggregatedSignature",
     "AggregationBits",
+    "Attestation",
+    "AttestationData",
+    "AttestationsByValidator",
+    "SignedAttestation",
 ]
diff --git a/src/lean_spec/subspecs/containers/attestation/attestation.py b/src/lean_spec/subspecs/containers/attestation/attestation.py
index dedc6f7d..be6acb34 100644
--- a/src/lean_spec/subspecs/containers/attestation/attestation.py
+++ b/src/lean_spec/subspecs/containers/attestation/attestation.py
@@ -22,7 +22,7 @@
 
 from ...xmss.containers import Signature
 from ..checkpoint import Checkpoint
-from .types import AggregationBits, NaiveAggregatedSignature
+from .types import AggregationBits
 
 
 class AttestationData(Container):
@@ -107,22 +107,3 @@ def aggregate_by_data(
             )
             for data, validator_ids in data_to_validator_ids.items()
         ]
-
-
-class SignedAggregatedAttestation(Container):
-    """Aggregated attestation bundled with aggregated signatures."""
-
-    message: AggregatedAttestation
-    """Aggregated attestation data."""
-
-    signature: NaiveAggregatedSignature
-    """Aggregated attestation plus its combined signature.
-
-    Stores a naive list of validator signatures that mirrors the attestation
-    order.
-
-    TODO:
-    - signatures will be replaced by MegaBytes in next PR to include leanVM proof.
-    - this will be replaced by a SNARK in future devnets.
-    - this will be aggregated by aggregators in future devnets.
-    """
diff --git a/src/lean_spec/subspecs/containers/attestation/types.py b/src/lean_spec/subspecs/containers/attestation/types.py
index 8304db5f..0e34c6b6 100644
--- a/src/lean_spec/subspecs/containers/attestation/types.py
+++ b/src/lean_spec/subspecs/containers/attestation/types.py
@@ -2,11 +2,18 @@
 
 from __future__ import annotations
 
-from lean_spec.types import SSZList, Uint64
+from typing import TYPE_CHECKING
+
+from lean_spec.types import Uint64
 from lean_spec.types.bitfields import BaseBitlist
 
 from ...chain.config import VALIDATOR_REGISTRY_LIMIT
-from ...xmss.containers import Signature
+
+if TYPE_CHECKING:
+    from .attestation import AttestationData
+
+AttestationsByValidator = dict[Uint64, "AttestationData"]
+"""Mapping from validator index to attestation data."""
 
 
 class AggregationBits(BaseBitlist):
@@ -57,10 +64,3 @@ def to_validator_indices(self) -> list[Uint64]:
             raise AssertionError("Aggregated attestation must reference at least one validator")
 
         return indices
-
-
-class NaiveAggregatedSignature(SSZList[Signature]):
-    """Naive list of validator signatures used for aggregation placeholders."""
-
-    ELEMENT_TYPE = Signature
-    LIMIT = int(VALIDATOR_REGISTRY_LIMIT)
diff --git a/src/lean_spec/subspecs/containers/block/__init__.py b/src/lean_spec/subspecs/containers/block/__init__.py
index 4ed7dfa7..50f5299a 100644
--- a/src/lean_spec/subspecs/containers/block/__init__.py
+++ b/src/lean_spec/subspecs/containers/block/__init__.py
@@ -11,12 +11,14 @@
 from .types import (
     AggregatedAttestations,
     AttestationSignatures,
+    BlockLookup,
 )
 
 __all__ = [
     "Block",
     "BlockBody",
     "BlockHeader",
+    "BlockLookup",
     "BlockSignatures",
     "BlockWithAttestation",
     "SignedBlockWithAttestation",
diff --git a/src/lean_spec/subspecs/containers/block/types.py b/src/lean_spec/subspecs/containers/block/types.py
index 39fb4e03..e16a93d9 100644
--- a/src/lean_spec/subspecs/containers/block/types.py
+++ b/src/lean_spec/subspecs/containers/block/types.py
@@ -1,11 +1,21 @@
 """Block-specific SSZ types for the Lean Ethereum consensus specification."""
 
+from __future__ import annotations
+
+from typing import TYPE_CHECKING
+
 from lean_spec.subspecs.xmss.aggregation import MultisigAggregatedSignature
-from lean_spec.types import SSZList
+from lean_spec.types import Bytes32, SSZList
 
 from ...chain.config import VALIDATOR_REGISTRY_LIMIT
 from ..attestation import AggregatedAttestation
 
+if TYPE_CHECKING:
+    from .block import Block
+
+BlockLookup = dict[Bytes32, "Block"]
+"""Mapping from block root to Block objects."""
+
 
 class AggregatedAttestations(SSZList[AggregatedAttestation]):
     """List of aggregated attestations included in a block."""
diff --git a/src/lean_spec/subspecs/containers/state/__init__.py b/src/lean_spec/subspecs/containers/state/__init__.py
index 8fe22bb6..4bda075e 100644
--- a/src/lean_spec/subspecs/containers/state/__init__.py
+++ b/src/lean_spec/subspecs/containers/state/__init__.py
@@ -2,11 +2,6 @@
 
 from .state import State
 from .types import (
-    AggregatedSignaturePayload,
-    AggregatedSignaturePayloads,
-    AttestationsByValidator,
-    AttestationSignatureKey,
-    BlockLookup,
     HistoricalBlockHashes,
     JustificationRoots,
     JustificationValidators,
@@ -16,16 +11,11 @@
 )
 
 __all__ = [
-    "State",
-    "AggregatedSignaturePayload",
-    "AggregatedSignaturePayloads",
-    "AttestationSignatureKey",
-    "AttestationsByValidator",
-    "BlockLookup",
     "HistoricalBlockHashes",
     "JustificationRoots",
     "JustificationValidators",
     "JustifiedSlots",
+    "State",
     "StateLookup",
     "Validators",
 ]
diff --git a/src/lean_spec/subspecs/containers/state/state.py b/src/lean_spec/subspecs/containers/state/state.py
index 0f6dc864..7eb33fb4 100644
--- a/src/lean_spec/subspecs/containers/state/state.py
+++ b/src/lean_spec/subspecs/containers/state/state.py
@@ -3,7 +3,11 @@
 from typing import AbstractSet, Iterable
 
 from lean_spec.subspecs.ssz.hash import hash_tree_root
-from lean_spec.subspecs.xmss.aggregation import MultisigAggregatedSignature
+from lean_spec.subspecs.xmss.aggregation import (
+    AggregatedSignaturePayloads,
+    AttestationSignatureKey,
+    MultisigAggregatedSignature,
+)
 from lean_spec.subspecs.xmss.containers import PublicKey, Signature
 from lean_spec.types import (
     ZERO_HASH,
@@ -21,8 +25,6 @@
 from ..config import Config
 from ..slot import Slot
 from .types import (
-    AggregatedSignaturePayloads,
-    AttestationSignatureKey,
     HistoricalBlockHashes,
     JustificationRoots,
     JustificationValidators,
diff --git a/src/lean_spec/subspecs/containers/state/types.py b/src/lean_spec/subspecs/containers/state/types.py
index e081f969..33122848 100644
--- a/src/lean_spec/subspecs/containers/state/types.py
+++ b/src/lean_spec/subspecs/containers/state/types.py
@@ -5,36 +5,17 @@
 from typing import TYPE_CHECKING
 
 from lean_spec.subspecs.chain.config import DEVNET_CONFIG
-from lean_spec.subspecs.xmss.aggregation import MultisigAggregatedSignature
-from lean_spec.types import Bytes32, SSZList, Uint64
+from lean_spec.types import Bytes32, SSZList
 from lean_spec.types.bitfields import BaseBitlist
 
-from ..attestation import AggregationBits, AttestationData
-from ..block import Block
 from ..validator import Validator
 
 if TYPE_CHECKING:
     from .state import State
 
-# Type aliases for signature aggregation
-AttestationSignatureKey = tuple[Uint64, bytes]
-"""Key type for looking up signatures: (validator_id, attestation_data_root)."""
-
-AggregatedSignaturePayload = tuple[AggregationBits, MultisigAggregatedSignature]
-"""Aggregated signature payload with its participant bitlist."""
-
-AggregatedSignaturePayloads = list[AggregatedSignaturePayload]
-"""List of aggregated signature payloads with their participant bitlists."""
-
-BlockLookup = dict[Bytes32, Block]
-"""Mapping from block root to Block objects."""
-
 StateLookup = dict[Bytes32, "State"]
 """Mapping from state root to State objects."""
 
-AttestationsByValidator = dict[Uint64, AttestationData]
-"""Mapping from validator index to attestation data."""
-
 
 class HistoricalBlockHashes(SSZList[Bytes32]):
     """List of historical block root hashes up to historical_roots_limit."""
diff --git a/src/lean_spec/subspecs/forkchoice/store.py b/src/lean_spec/subspecs/forkchoice/store.py
index 78eb08a2..bf0e07ac 100644
--- a/src/lean_spec/subspecs/forkchoice/store.py
+++ b/src/lean_spec/subspecs/forkchoice/store.py
@@ -25,6 +25,7 @@
     AggregationBits,
     Attestation,
     AttestationData,
+    AttestationsByValidator,
     Block,
     Checkpoint,
     Config,
@@ -32,16 +33,15 @@
     SignedBlockWithAttestation,
     State,
 )
+from lean_spec.subspecs.containers.block import BlockLookup
 from lean_spec.subspecs.containers.slot import Slot
-from lean_spec.subspecs.containers.state.types import (
+from lean_spec.subspecs.containers.state import StateLookup
+from lean_spec.subspecs.ssz.hash import hash_tree_root
+from lean_spec.subspecs.xmss.aggregation import (
     AggregatedSignaturePayloads,
-    AttestationsByValidator,
     AttestationSignatureKey,
-    BlockLookup,
-    StateLookup,
+    MultisigAggregatedSignature,
 )
-from lean_spec.subspecs.ssz.hash import hash_tree_root
-from lean_spec.subspecs.xmss.aggregation import MultisigAggregatedSignature
 from lean_spec.subspecs.xmss.containers import Signature
 from lean_spec.subspecs.xmss.interface import TARGET_SIGNATURE_SCHEME, GeneralizedXmssScheme
 from lean_spec.types import (
diff --git a/src/lean_spec/subspecs/xmss/aggregation.py b/src/lean_spec/subspecs/xmss/aggregation.py
index 0da86fd2..9cbe813c 100644
--- a/src/lean_spec/subspecs/xmss/aggregation.py
+++ b/src/lean_spec/subspecs/xmss/aggregation.py
@@ -7,7 +7,7 @@
 
 from __future__ import annotations
 
-from typing import Self, Sequence
+from typing import TYPE_CHECKING, Self, Sequence
 
 from lean_multisig_py import aggregate_signatures as aggregate_signatures_py
 from lean_multisig_py import setup_prover, setup_verifier
@@ -18,6 +18,12 @@
 from lean_spec.types import Uint64
 from lean_spec.types.byte_arrays import ByteListMiB
 
+if TYPE_CHECKING:
+    from lean_spec.subspecs.containers.attestation import AggregationBits
+
+AttestationSignatureKey = tuple[Uint64, bytes]
+"""Key type for looking up signatures: (validator id, attestation data root)."""
+
 
 class MultisigError(RuntimeError):
     """Base exception for multisig aggregation helpers."""
@@ -108,3 +114,10 @@ def verify_aggregated_payload(
             )
         except Exception as exc:
             raise MultisigAggregationError(f"Multisig verification failed: {exc}") from exc
+
+
+AggregatedSignaturePayload = tuple["AggregationBits", "MultisigAggregatedSignature"]
+"""Aggregated signature payload with its participant bitlist."""
+
+AggregatedSignaturePayloads = list[AggregatedSignaturePayload]
+"""List of aggregated signature payloads with their participant bitlists."""