diff --git a/crates/blockchain/src/store.rs b/crates/blockchain/src/store.rs
index 04138a91..a7208dac 100644
--- a/crates/blockchain/src/store.rs
+++ b/crates/blockchain/src/store.rs
@@ -7,9 +7,11 @@ use ethlambda_state_transition::{
 use ethlambda_storage::{ForkCheckpoints, SignatureKey, Store};
 use ethlambda_types::{
     ShortRoot,
-    attestation::{AggregatedAttestation, Attestation, AttestationData, SignedAttestation},
+    attestation::{
+        AggregatedAttestation, AggregationBits, Attestation, AttestationData, SignedAttestation,
+    },
     block::{
-        AggregatedAttestations, AggregatedSignatureProof, AggregationBits, Block, BlockBody,
+        AggregatedAttestations, AggregatedSignatureProof, Block, BlockBody,
         SignedBlockWithAttestation,
     },
     primitives::{H256, ssz::TreeHash},
diff --git a/crates/blockchain/tests/signature_types.rs b/crates/blockchain/tests/signature_types.rs
index 31d03c66..b52e2b32 100644
--- a/crates/blockchain/tests/signature_types.rs
+++ b/crates/blockchain/tests/signature_types.rs
@@ -1,8 +1,8 @@
 use super::common::{AggregationBits, Block, Container, ProposerAttestation, TestInfo, TestState};
-use ethlambda_types::attestation::XmssSignature;
+use ethlambda_types::attestation::{AggregationBits as EthAggregationBits, XmssSignature};
 use ethlambda_types::block::{
-    AggregatedSignatureProof, AggregationBits as EthAggregationBitsSig, AttestationSignatures,
-    BlockSignatures, BlockWithAttestation, SignedBlockWithAttestation,
+    AggregatedSignatureProof, AttestationSignatures, BlockSignatures, BlockWithAttestation,
+    SignedBlockWithAttestation,
 };
 use ethlambda_types::primitives::ssz::{Decode as SszDecode, Encode as SszEncode};
 use serde::Deserialize;
@@ -104,7 +104,7 @@ impl From<TestSignedBlockWithAttestation> for SignedBlockWithAttestation {
             .into_iter()
             .map(|att_sig| {
                 // Convert participants bitfield
-                let participants: EthAggregationBitsSig = att_sig.participants.into();
+                let participants: EthAggregationBits = att_sig.participants.into();
                 // Create proof with participants but empty proof_data
                 AggregatedSignatureProof::empty(participants)
             })
diff --git a/crates/common/types/src/block.rs b/crates/common/types/src/block.rs
index 776dbb1e..634c7953 100644
--- a/crates/common/types/src/block.rs
+++ b/crates/common/types/src/block.rs
@@ -2,7 +2,7 @@ use serde::Serialize;
 use ssz_types::typenum::U1048576;
 
 use crate::{
-    attestation::{AggregatedAttestation, Attestation, XmssSignature},
+    attestation::{AggregatedAttestation, AggregationBits, Attestation, XmssSignature},
     primitives::{
         ByteList, H256,
         ssz::{Decode, Encode, TreeHash},
@@ -102,24 +102,8 @@ impl AggregatedSignatureProof {
             proof_data: ByteList::empty(),
         }
     }
-
-    /// Get the participants bitfield.
-    pub fn participants(&self) -> &AggregationBits {
-        &self.participants
-    }
-
-    /// Get the proof data.
-    pub fn proof_data(&self) -> &ByteListMiB {
-        &self.proof_data
-    }
 }
 
-/// Bitlist representing validator participation in an attestation or signature.
-///
-/// A general-purpose bitfield for tracking which validators have participated
-/// in some collective action (attestation, signature aggregation, etc.).
-pub type AggregationBits = ssz_types::BitList<ValidatorRegistryLimit>;
-
 /// Bundle containing a block and the proposer's attestation.
 #[derive(Debug, Clone, Encode, Decode, TreeHash)]
 pub struct BlockWithAttestation {