diff --git a/src/api.rs b/src/api.rs
index 90fac8c..de9c0a0 100644
--- a/src/api.rs
+++ b/src/api.rs
@@ -104,6 +104,7 @@ pub struct UserDiff {
     pub notify_user: bool,
     pub need_validation: bool,
     pub validation_status: DiffStatus,
+    pub storages: Vec<String>,
 }
 
 #[derive(Debug, PartialEq, Tsify, Serialize, Deserialize, Default)]
@@ -705,17 +706,34 @@ fn create_diffs(device: &MutexGuard<Device>, process: &Process, new_state: &Proc
 
     let our_id = device.get_pairing_commitment();
 
-    let fields_to_validate = if let Some(our_id) = our_id {
-        new_state.get_fields_to_validate_for_member(&our_id)?
+    let fields_to_validate: HashMap<String, Vec<String>> = if let Some(our_id) = our_id {
+        let mut relevant_fields = HashMap::new();
+        for (name, role) in new_state.roles.iter() {
+            if !role.members.contains(&our_id) {
+                // This role doesn't concern requester
+                continue;
+            }
+            let fields: Vec<String> = role
+                .validation_rules
+                .iter()
+                .flat_map(|rule| rule.fields.clone())
+                .collect();
+            relevant_fields.extend(fields.into_iter().map(|field| (field, role.storages.clone())));
+        }
+        relevant_fields
     } else {
         // Device is unpaired, we just take all the fields in the `pairing` role
         if let Some(pairing_role) = new_state.roles.get("pairing") {
-            pairing_role.validation_rules.iter().flat_map(|r| r.fields.clone()).collect()
+            let mut relevant_fields = HashMap::new();
+            let fields: Vec<String> = pairing_role.validation_rules.iter().flat_map(|r| r.fields.clone()).collect();
+            relevant_fields.extend(fields.into_iter().map(|field| (field, pairing_role.storages.clone())));
+            relevant_fields
         } else {
             return Err(AnyhowError::msg("Missing pairing role"))
         }
     };
 
+
     let new_state_id = &new_state.state_id;
 
     let new_public_data = &new_state.public_data;
@@ -723,7 +741,7 @@ fn create_diffs(device: &MutexGuard<Device>, process: &Process, new_state: &Proc
     let process_id = process.get_process_id()?.to_string();
     let mut diffs = vec![];
     for (field, hash) in new_state_commitments.iter() {
-        let need_validation = fields_to_validate.contains(field);
+        let need_validation = fields_to_validate.contains_key(field);
         diffs.push(UserDiff {
             process_id: process_id.clone(),
             state_id: new_state_id.to_lower_hex_string(),
@@ -734,6 +752,7 @@ fn create_diffs(device: &MutexGuard<Device>, process: &Process, new_state: &Proc
             need_validation,
             validation_status: DiffStatus::None,
             roles: new_state.roles.clone(),
+            storages: fields_to_validate.get(field).unwrap_or(&vec![]).clone(),
         });
     }
 
@@ -944,7 +963,7 @@ fn handle_prd(
                 let sp_wallet = local_device.get_sp_client();
                 let local_address = sp_wallet.get_receiving_address().to_string();
 
-                let mut relevant_fields: HashSet<String> = HashSet::new();
+                let mut relevant_fields: HashMap<String, Vec<String>> = HashMap::new();
                 let shared_secrets = lock_shared_secrets()?;
                 for (name, role) in state.roles.iter() {
                     if !role.members.contains(&requester) {
@@ -956,7 +975,7 @@ fn handle_prd(
                         .iter()
                         .flat_map(|rule| rule.fields.clone())
                         .collect();
-                    relevant_fields.extend(fields);
+                    relevant_fields.extend(fields.into_iter().map(|field| (field, role.storages.clone())));
                 }
 
                 let sender = local_device.get_pairing_commitment().ok_or(AnyhowError::msg("Device not paired"))?;
@@ -970,7 +989,7 @@ fn handle_prd(
                     state.pcd_commitment.clone(),
                 );
 
-                full_prd.filter_keys(&relevant_fields);
+                full_prd.filter_keys(&relevant_fields.iter().map(|(field, _)| field.clone()).collect());
                 let prd_msg = full_prd.to_network_msg(sp_wallet)?;
 
                 let addresses = members_list.0.get(&sender).ok_or(AnyhowError::msg("Unknown requester"))?.get_addresses();
@@ -991,7 +1010,7 @@ fn handle_prd(
                 let pcd_commitment = &state.pcd_commitment;
                 for (field, hash) in pcd_commitment.iter() {
                     // We only need field that are visible by requester
-                    if !relevant_fields.contains(field.as_str()) {
+                    if !relevant_fields.contains_key(field.as_str()) {
                         continue;
                     }
                     let diff = UserDiff {
@@ -999,6 +1018,7 @@ fn handle_prd(
                         state_id: state_id.to_lower_hex_string(),
                         value_commitment: hash.to_lower_hex_string(),
                         field: field.to_owned(),
+                        storages: relevant_fields.get(field.as_str()).unwrap().clone(),
                         ..Default::default()
                     };
                     diffs.push(diff);
@@ -1038,6 +1058,7 @@ fn handle_decrypted_message(
     }
 }
 
+// TODO make separate functions for the decryption itself and the parsing to avoid copy and serialization cost
 #[wasm_bindgen]
 pub fn parse_cipher(cipher_msg: String, members_list: OutPointMemberMap, processes: OutPointProcessMap) -> ApiResult<ApiReturn> {
     // Check that the cipher is not empty or too long