diff --git a/Cargo.lock b/Cargo.lock
index ddd13c0c..7b514a8c 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -2169,6 +2169,7 @@ dependencies = [
 name = "ethlambda-storage"
 version = "0.1.0"
 dependencies = [
+ "ethlambda-crypto",
  "ethlambda-types",
  "leansig",
  "libssz",
@@ -2201,7 +2202,6 @@ dependencies = [
  "datatest-stable 0.3.3",
  "ethlambda-test-fixtures",
  "hex",
- "leansig",
  "libssz",
  "libssz-derive",
  "libssz-merkle",
diff --git a/bin/ethlambda/src/main.rs b/bin/ethlambda/src/main.rs
index 33e242e9..df4893e6 100644
--- a/bin/ethlambda/src/main.rs
+++ b/bin/ethlambda/src/main.rs
@@ -36,6 +36,7 @@ use cli::CliOptions;
 use ethlambda_blockchain::MILLISECONDS_PER_SLOT;
 use ethlambda_blockchain::block_builder::ProposerConfig;
 use ethlambda_blockchain::key_manager::ValidatorKeyPair;
+use ethlambda_crypto::signature::ValidatorSecretKey;
 use ethlambda_network_api::{InitBlockChain, InitP2P, ToBlockChainToP2PRef, ToP2PToBlockChainRef};
 use ethlambda_p2p::{
     Bootnode, P2P, PeerId, SwarmConfig, attestation_subscription_subnets, build_swarm, parse_enrs,
@@ -44,7 +45,6 @@ use ethlambda_types::primitives::{H256, HashTreeRoot as _};
 use ethlambda_types::{
     aggregator::AggregatorController,
     genesis::GenesisConfig,
-    signature::ValidatorSecretKey,
     state::{State, ValidatorPubkeyBytes},
 };
 use eyre::WrapErr;
diff --git a/crates/blockchain/src/aggregation.rs b/crates/blockchain/src/aggregation.rs
index 2a62b2a6..4d5049b8 100644
--- a/crates/blockchain/src/aggregation.rs
+++ b/crates/blockchain/src/aggregation.rs
@@ -20,13 +20,13 @@ use std::collections::{HashMap, HashSet};
 use std::time::{Duration, Instant, SystemTime};
 
 use ethlambda_crypto::aggregate_mixed;
+use ethlambda_crypto::signature::{ValidatorPublicKey, ValidatorSignature};
 use ethlambda_storage::Store;
 use ethlambda_types::{
     ShortRoot,
     attestation::{AggregationBits, AttestationData, HashedAttestationData},
     block::{ByteList512KiB, SingleMessageAggregate},
     primitives::H256,
-    signature::{ValidatorPublicKey, ValidatorSignature},
     state::Validator,
 };
 use spawned_concurrency::message::Message;
@@ -425,7 +425,7 @@ fn resolve_job(
         let Some(validator) = validators.get(*vid as usize) else {
             continue;
         };
-        let Ok(pubkey) = validator.get_attestation_pubkey() else {
+        let Ok(pubkey) = ValidatorPublicKey::from_bytes(&validator.attestation_pubkey) else {
             continue;
         };
         raw_by_id.insert(*vid, (pubkey, sig.clone()));
@@ -492,7 +492,10 @@ fn resolve_child_pubkeys(
         let participant_ids: Vec<u64> = proof.participant_indices().collect();
         let child_pubkeys: Vec<ValidatorPublicKey> = participant_ids
             .iter()
-            .filter_map(|&vid| validators.get(vid as usize)?.get_attestation_pubkey().ok())
+            .filter_map(|&vid| {
+                let v = validators.get(vid as usize)?;
+                ValidatorPublicKey::from_bytes(&v.attestation_pubkey).ok()
+            })
             .collect();
         if child_pubkeys.len() != participant_ids.len() {
             warn!(
@@ -796,7 +799,7 @@ mod tests {
     /// never checks signature validity, only that it clones and carries a
     /// resolvable id — mirrors `ethlambda_storage::store::tests::make_dummy_sig`.
     fn dummy_sig() -> ValidatorSignature {
-        use ethlambda_types::signature::LeanSignatureScheme;
+        use ethlambda_crypto::signature::LeanSignatureScheme;
         use leansig::{serialization::Serializable, signature::SignatureScheme};
         use rand::{SeedableRng, rngs::StdRng};
 
diff --git a/crates/blockchain/src/block_builder.rs b/crates/blockchain/src/block_builder.rs
index 787c55b4..4f0d62a6 100644
--- a/crates/blockchain/src/block_builder.rs
+++ b/crates/blockchain/src/block_builder.rs
@@ -15,7 +15,7 @@ use std::{
     time::Instant,
 };
 
-use ethlambda_crypto::aggregate_proofs;
+use ethlambda_crypto::{aggregate_proofs, signature::ValidatorPublicKey};
 use ethlambda_state_transition::{
     attestation_data_matches_chain, justified_slots_ops, process_block, process_slots,
     slot_is_justifiable_after,
@@ -657,11 +657,11 @@ fn compact_attestations(
                 let pubkeys = proof
                     .participant_indices()
                     .map(|vid| {
-                        head_state
+                        let validator = head_state
                             .validators
                             .get(vid as usize)
-                            .ok_or(StoreError::InvalidValidatorIndex)?
-                            .get_attestation_pubkey()
+                            .ok_or(StoreError::InvalidValidatorIndex)?;
+                        ValidatorPublicKey::from_bytes(&validator.attestation_pubkey)
                             .map_err(|_| StoreError::PubkeyDecodingFailed(vid))
                     })
                     .collect::<Result<Vec<_>, _>>()?;
diff --git a/crates/blockchain/src/key_manager.rs b/crates/blockchain/src/key_manager.rs
index cb58c354..eb2777a8 100644
--- a/crates/blockchain/src/key_manager.rs
+++ b/crates/blockchain/src/key_manager.rs
@@ -1,10 +1,10 @@
 use std::collections::HashMap;
 use std::time::Instant;
 
+use ethlambda_crypto::signature::{ValidatorSecretKey, ValidatorSignature};
 use ethlambda_types::{
     attestation::{AttestationData, XmssSignature},
     primitives::{H256, HashTreeRoot as _},
-    signature::{ValidatorSecretKey, ValidatorSignature},
 };
 use tracing::{info, warn};
 
diff --git a/crates/blockchain/src/lib.rs b/crates/blockchain/src/lib.rs
index b2929ab6..abace771 100644
--- a/crates/blockchain/src/lib.rs
+++ b/crates/blockchain/src/lib.rs
@@ -1,6 +1,7 @@
 use std::collections::{HashMap, HashSet, VecDeque};
 use std::time::{Duration, Instant, SystemTime};
 
+use ethlambda_crypto::signature::{ValidatorPublicKey, ValidatorSignature};
 use ethlambda_network_api::{BlockChainToP2PRef, InitP2P};
 use ethlambda_state_transition::is_proposer;
 use ethlambda_storage::{ALL_TABLES, Store};
@@ -10,7 +11,6 @@ use ethlambda_types::{
     attestation::{SignedAggregatedAttestation, SignedAttestation},
     block::{ByteList512KiB, MultiMessageAggregate, SignedBlock},
     primitives::{H256, HashTreeRoot as _},
-    signature::{ValidatorPublicKey, ValidatorSignature},
 };
 
 use crate::aggregation::{
@@ -763,7 +763,10 @@ impl BlockChainServer {
         // Decode the proposer's proposal pubkey once and reuse it both for the
         // singleton single-message aggregate wrap and for the multi-message
         // aggregate merge inputs.
-        let Ok(proposer_pubkey) = proposer_validator.get_proposal_pubkey().inspect_err(
+        let Ok(proposer_pubkey) = ValidatorPublicKey::from_bytes(
+            &proposer_validator.proposal_pubkey,
+        )
+        .inspect_err(
             |err| error!(%slot, %validator_id, %err, "Failed to decode proposer proposal pubkey"),
         ) else {
             metrics::inc_block_building_failures();
@@ -802,7 +805,7 @@ impl BlockChainServer {
                     resolve_failed = true;
                     break;
                 };
-                match validator.get_attestation_pubkey() {
+                match ValidatorPublicKey::from_bytes(&validator.attestation_pubkey) {
                     Ok(pk) => pubkeys.push(pk),
                     Err(err) => {
                         error!(%slot, %validator_id, vid, %err, "Failed to decode attestation pubkey");
diff --git a/crates/blockchain/src/reaggregate.rs b/crates/blockchain/src/reaggregate.rs
index f47d6c51..64e762e7 100644
--- a/crates/blockchain/src/reaggregate.rs
+++ b/crates/blockchain/src/reaggregate.rs
@@ -24,6 +24,7 @@
 
 use std::collections::HashSet;
 
+use ethlambda_crypto::signature::ValidatorPublicKey;
 use ethlambda_storage::Store;
 use ethlambda_types::{
     attestation::{
@@ -32,7 +33,6 @@ use ethlambda_types::{
     },
     block::{SignedBlock, SingleMessageAggregate},
     primitives::{H256, HashTreeRoot as _},
-    signature::ValidatorPublicKey,
 };
 use tracing::{debug, warn};
 
@@ -83,7 +83,9 @@ pub fn reaggregate_from_block(
                 warn!(vid, "Reaggregation aborted: participant out of range");
                 return Vec::new();
             }
-            let Ok(pk) = validators[vid as usize].get_attestation_pubkey() else {
+            let Ok(pk) =
+                ValidatorPublicKey::from_bytes(&validators[vid as usize].attestation_pubkey)
+            else {
                 warn!(vid, "Reaggregation aborted: bad attestation pubkey");
                 return Vec::new();
             };
@@ -94,7 +96,8 @@ pub fn reaggregate_from_block(
     if block.proposer_index >= num_validators {
         return Vec::new();
     }
-    let Ok(proposer_pubkey) = validators[block.proposer_index as usize].get_proposal_pubkey()
+    let Ok(proposer_pubkey) =
+        ValidatorPublicKey::from_bytes(&validators[block.proposer_index as usize].proposal_pubkey)
     else {
         return Vec::new();
     };
@@ -161,7 +164,9 @@ pub fn reaggregate_from_block(
                         bad = true;
                         break;
                     }
-                    match validators[vid as usize].get_attestation_pubkey() {
+                    match ValidatorPublicKey::from_bytes(
+                        &validators[vid as usize].attestation_pubkey,
+                    ) {
                         Ok(pk) => pubkeys.push(pk),
                         Err(_) => {
                             bad = true;
diff --git a/crates/blockchain/src/store.rs b/crates/blockchain/src/store.rs
index 2bdf46b0..1a6d3884 100644
--- a/crates/blockchain/src/store.rs
+++ b/crates/blockchain/src/store.rs
@@ -1,5 +1,6 @@
 use std::collections::{HashMap, HashSet};
 
+use ethlambda_crypto::signature::{ValidatorPublicKey, ValidatorSignature};
 use ethlambda_state_transition::{is_proposer, slot_is_justifiable_after};
 use ethlambda_storage::{ForkCheckpoints, Store};
 use ethlambda_types::{
@@ -11,7 +12,6 @@ use ethlambda_types::{
     block::{Block, BlockHeader, SignedBlock, SingleMessageAggregate},
     checkpoint::Checkpoint,
     primitives::{H256, HashTreeRoot as _},
-    signature::{ValidatorPublicKey, ValidatorSignature},
     state::{HISTORICAL_ROOTS_LIMIT, State},
 };
 use tracing::{info, trace, warn};
@@ -418,9 +418,10 @@ pub fn on_gossip_attestation(
     if validator_id >= target_state.validators.len() as u64 {
         return Err(StoreError::InvalidValidatorIndex);
     }
-    let validator_pubkey = target_state.validators[validator_id as usize]
-        .get_attestation_pubkey()
-        .map_err(|_| StoreError::PubkeyDecodingFailed(validator_id))?;
+    let validator_pubkey = ValidatorPublicKey::from_bytes(
+        &target_state.validators[validator_id as usize].attestation_pubkey,
+    )
+    .map_err(|_| StoreError::PubkeyDecodingFailed(validator_id))?;
 
     // Verify the validator's XMSS signature
     let slot: u32 = attestation.data.slot.try_into().expect("slot exceeds u32");
@@ -513,8 +514,7 @@ fn on_gossip_aggregated_attestation_core(
     let pubkeys: Vec<_> = participant_indices
         .iter()
         .map(|&vid| {
-            validators[vid as usize]
-                .get_attestation_pubkey()
+            ValidatorPublicKey::from_bytes(&validators[vid as usize].attestation_pubkey)
                 .map_err(|_| StoreError::PubkeyDecodingFailed(vid))
         })
         .collect::<Result<_, _>>()?;
@@ -1142,8 +1142,7 @@ pub fn verify_block_signatures(
             let validator = validators
                 .get(vid as usize)
                 .ok_or(StoreError::InvalidValidatorIndex)?;
-            let pk = validator
-                .get_attestation_pubkey()
+            let pk = ValidatorPublicKey::from_bytes(&validator.attestation_pubkey)
                 .map_err(|_| StoreError::PubkeyDecodingFailed(vid))?;
             pubkeys.push(pk);
         }
@@ -1156,8 +1155,7 @@ pub fn verify_block_signatures(
     let proposer_validator = validators
         .get(block.proposer_index as usize)
         .ok_or(StoreError::InvalidValidatorIndex)?;
-    let proposer_pubkey = proposer_validator
-        .get_proposal_pubkey()
+    let proposer_pubkey = ValidatorPublicKey::from_bytes(&proposer_validator.proposal_pubkey)
         .map_err(|_| StoreError::PubkeyDecodingFailed(block.proposer_index))?;
     pubkeys_per_component.push(vec![proposer_pubkey]);
     let block_slot_u32 =
diff --git a/crates/common/crypto/src/lib.rs b/crates/common/crypto/src/lib.rs
index 4e081445..51d7d282 100644
--- a/crates/common/crypto/src/lib.rs
+++ b/crates/common/crypto/src/lib.rs
@@ -1,10 +1,8 @@
 use std::sync::Once;
 
-use ethlambda_types::{
-    block::ByteList512KiB,
-    primitives::H256,
-    signature::{ValidatorPublicKey, ValidatorSignature},
-};
+use ethlambda_types::{block::ByteList512KiB, primitives::H256};
+
+use crate::signature::{ValidatorPublicKey, ValidatorSignature};
 use lean_multisig::{
     MultiMessageAggregateSignature as LMType2, ProofError,
     SingleMessageAggregateSignature as LMType1, aggregate_single_message_signatures,
@@ -14,6 +12,8 @@ use lean_multisig::{
 use leansig_wrapper::{XmssPublicKey as LeanSigPubKey, XmssSignature as LeanSigSignature};
 use thiserror::Error;
 
+pub mod signature;
+
 #[cfg(feature = "shadow-integration")]
 pub mod shadow_cost;
 
@@ -508,7 +508,7 @@ pub fn split_type_2_by_message(
 #[cfg(test)]
 mod tests {
     use super::*;
-    use ethlambda_types::signature::LeanSignatureScheme;
+    use crate::signature::LeanSignatureScheme;
     use leansig::{serialization::Serializable, signature::SignatureScheme};
     use rand::{SeedableRng, rngs::StdRng};
 
diff --git a/crates/common/types/src/signature.rs b/crates/common/crypto/src/signature.rs
similarity index 97%
rename from crates/common/types/src/signature.rs
rename to crates/common/crypto/src/signature.rs
index fa9c8da8..39515e53 100644
--- a/crates/common/types/src/signature.rs
+++ b/crates/common/crypto/src/signature.rs
@@ -1,12 +1,14 @@
+//! Validator XMSS signatures, public/secret keys, and the leansig-backed
+//! primitives behind them.
+
 use std::ops::Range;
 
+use ethlambda_types::primitives::H256;
 use leansig::{
     serialization::Serializable,
     signature::{SignatureScheme, SignatureSchemeSecretKey as _, SigningError},
 };
 
-use crate::primitives::H256;
-
 /// The XMSS signature scheme used for validator signatures.
 ///
 /// This is a post-quantum secure signature scheme based on hash functions.
@@ -25,11 +27,6 @@ pub type LeanSigSecretKey = <LeanSignatureScheme as SignatureScheme>::SecretKey;
 
 pub type Signature = LeanSigSignature;
 
-/// Size of an XMSS signature in bytes.
-///
-/// Computed from: path(32*8*4) + rho(7*4) + hashes(46*8*4) + ssz_offsets(3*4) = 2536
-pub const SIGNATURE_SIZE: usize = 2536;
-
 /// Error returned when parsing signature or key bytes fails.
 #[derive(Debug, Clone, thiserror::Error)]
 #[error("signature parse error: {0}")]
diff --git a/crates/common/test-fixtures/src/common.rs b/crates/common/test-fixtures/src/common.rs
index 6293b897..6705292b 100644
--- a/crates/common/test-fixtures/src/common.rs
+++ b/crates/common/test-fixtures/src/common.rs
@@ -2,12 +2,11 @@ use ethlambda_types::{
     attestation::{
         AggregatedAttestation as DomainAggregatedAttestation,
         AggregationBits as DomainAggregationBits, AttestationData as DomainAttestationData,
-        XmssSignature,
+        SIGNATURE_SIZE, XmssSignature,
     },
     block::{Block as DomainBlock, BlockBody as DomainBlockBody},
     checkpoint::Checkpoint as DomainCheckpoint,
     primitives::H256,
-    signature::SIGNATURE_SIZE,
     state::{
         ChainConfig, JustificationValidators, JustifiedSlots, State, Validator as DomainValidator,
         ValidatorPubkeyBytes,
diff --git a/crates/common/types/Cargo.toml b/crates/common/types/Cargo.toml
index 1de09a67..383f77a3 100644
--- a/crates/common/types/Cargo.toml
+++ b/crates/common/types/Cargo.toml
@@ -14,8 +14,6 @@ thiserror.workspace = true
 serde.workspace = true
 hex.workspace = true
 
-leansig.workspace = true
-
 libssz.workspace = true
 libssz-derive.workspace = true
 libssz-merkle.workspace = true
diff --git a/crates/common/types/src/attestation.rs b/crates/common/types/src/attestation.rs
index 0d68addb..91d00105 100644
--- a/crates/common/types/src/attestation.rs
+++ b/crates/common/types/src/attestation.rs
@@ -7,7 +7,6 @@ use crate::{
     block::SingleMessageAggregate,
     checkpoint::Checkpoint,
     primitives::{H256, HashTreeRoot as _},
-    signature::SIGNATURE_SIZE,
 };
 
 /// Validator specific attestation wrapping shared attestation data.
@@ -55,6 +54,13 @@ pub struct SignedAttestation {
     pub signature: XmssSignature,
 }
 
+/// Size of an XMSS signature in bytes.
+///
+/// Computed from: path(32*8*4) + rho(7*4) + hashes(46*8*4) + ssz_offsets(3*4) = 2536.
+/// This is the SSZ wire size, independent of the `leansig` scheme itself, so it
+/// lives here (leansig-free) rather than in `ethlambda-crypto`.
+pub const SIGNATURE_SIZE: usize = 2536;
+
 /// XMSS signature as a fixed-length byte vector (`SIGNATURE_SIZE` bytes).
 pub type XmssSignature = SszVector<u8, SIGNATURE_SIZE>;
 
diff --git a/crates/common/types/src/lib.rs b/crates/common/types/src/lib.rs
index 6db9a590..88ba98b9 100644
--- a/crates/common/types/src/lib.rs
+++ b/crates/common/types/src/lib.rs
@@ -5,7 +5,6 @@ pub mod checkpoint;
 pub mod constants;
 pub mod genesis;
 pub mod primitives;
-pub mod signature;
 pub mod state;
 
 /// Display helper for truncated root hashes (8 hex chars)
diff --git a/crates/common/types/src/state.rs b/crates/common/types/src/state.rs
index 26ff110d..6cc25bb4 100644
--- a/crates/common/types/src/state.rs
+++ b/crates/common/types/src/state.rs
@@ -6,7 +6,6 @@ use crate::{
     block::{Block, BlockBody, BlockHeader},
     checkpoint::Checkpoint,
     primitives::{self, H256},
-    signature::{SignatureParseError, ValidatorPublicKey},
 };
 
 // Convenience trait for calling hash_tree_root() without a hasher argument
@@ -85,16 +84,6 @@ where
     serializer.serialize_str(&hex::encode(pubkey))
 }
 
-impl Validator {
-    pub fn get_attestation_pubkey(&self) -> Result<ValidatorPublicKey, SignatureParseError> {
-        ValidatorPublicKey::from_bytes(&self.attestation_pubkey)
-    }
-
-    pub fn get_proposal_pubkey(&self) -> Result<ValidatorPublicKey, SignatureParseError> {
-        ValidatorPublicKey::from_bytes(&self.proposal_pubkey)
-    }
-}
-
 pub type ValidatorPubkeyBytes = [u8; 52];
 
 impl State {
diff --git a/crates/storage/Cargo.toml b/crates/storage/Cargo.toml
index 7381a53e..035d802a 100644
--- a/crates/storage/Cargo.toml
+++ b/crates/storage/Cargo.toml
@@ -10,6 +10,7 @@ rust-version.workspace = true
 version.workspace = true
 
 [dependencies]
+ethlambda-crypto.workspace = true
 ethlambda-types.workspace = true
 
 tracing.workspace = true
diff --git a/crates/storage/src/store.rs b/crates/storage/src/store.rs
index 83f1e8fc..d5cac0ed 100644
--- a/crates/storage/src/store.rs
+++ b/crates/storage/src/store.rs
@@ -7,6 +7,7 @@ use lru::LruCache;
 use crate::api::{StorageBackend, StorageReadView, StorageWriteBatch, Table};
 use crate::error::Error;
 
+use ethlambda_crypto::signature::ValidatorSignature;
 use ethlambda_types::{
     attestation::{AggregationBits, AttestationData, HashedAttestationData, bits_is_subset},
     block::{
@@ -14,7 +15,6 @@ use ethlambda_types::{
     },
     checkpoint::Checkpoint,
     primitives::{H256, HashTreeRoot as _},
-    signature::ValidatorSignature,
     state::{ChainConfig, State, anchor_pair_is_consistent},
 };
 use libssz::{SszDecode, SszEncode};
@@ -2695,7 +2695,7 @@ mod tests {
     // ============ GossipSignatureBuffer Tests ============
 
     fn make_dummy_sig() -> ValidatorSignature {
-        use ethlambda_types::signature::LeanSignatureScheme;
+        use ethlambda_crypto::signature::LeanSignatureScheme;
         use leansig::{serialization::Serializable, signature::SignatureScheme};
         use rand::{SeedableRng, rngs::StdRng};