diff --git a/src/process.rs b/src/process.rs
index 9748c80..7180a7c 100644
--- a/src/process.rs
+++ b/src/process.rs
@@ -2,8 +2,8 @@ use std::{
     collections::{BTreeMap, HashMap, HashSet}, str::FromStr, sync::{Mutex, MutexGuard, OnceLock}
 };
 
+use ciborium::from_reader;
 use serde::{Deserialize, Serialize};
-use serde_json::Value;
 use sp_client::{bitcoin::{OutPoint, Transaction}, silentpayments::SilentPaymentAddress};
 use tsify::Tsify;
 
@@ -11,17 +11,6 @@ use crate::{
     pcd::{Member, Pcd, PcdCommitments, RoleDefinition, Roles, ValidationRule}, serialization::{deserialize_hex, hex_array_btree, serialize_hex, OutPointMemberMap}, signature::{AnkHash, AnkValidationNoHash, AnkValidationYesHash, Proof}, MutexExt, SpecialRoles, APOPHIS, PAIREDADDRESSES, PAIRING
 };
 
-fn extract_paired_addresses(paired_addresses: &Value) -> anyhow::Result<Vec<SilentPaymentAddress>> {
-    let array = paired_addresses.as_array().ok_or(anyhow::Error::msg("pairedAddresses is not an array"))?;
-    let sp_array: anyhow::Result<Vec<SilentPaymentAddress>> = array.into_iter().map(|value| {
-        let str = value.as_str().ok_or(anyhow::Error::msg("array contains a non string value"))?;
-        let sp_address = SilentPaymentAddress::try_from(str)?;
-        Ok(sp_address)
-    })
-    .collect();
-    sp_array
-}
-
 #[derive(Debug, Clone, Default, PartialEq, Serialize, Deserialize, Tsify)]
 #[tsify(into_wasm_abi, from_wasm_abi)]
 pub struct ProcessState {
@@ -43,6 +32,7 @@ pub struct ProcessState {
 
 impl ProcessState {
     pub fn new(commited_in: OutPoint, private_data: Pcd, public_data: Pcd, roles: Roles) -> anyhow::Result<Self> { 
+        // TODO check that we don't have duplicated field names in private and public data, nor a "roles" field name
         let all_attributes = Pcd::new(private_data.clone().into_iter().chain(public_data.clone()).collect());
         let pcd_commitment = PcdCommitments::new(&commited_in, &all_attributes, &roles)?;
 
@@ -61,15 +51,19 @@ impl ProcessState {
         Ok(res)
     }
 
-    pub fn update_value(&mut self, key: &str, new_value: &Value) -> anyhow::Result<()> {
+    pub fn update_value(&mut self, key: &str, new_value: &[u8]) -> anyhow::Result<()> {
         // Update the commitment
-        self.pcd_commitment.update_with_value(&self.commited_in, key, new_value)?;
+        let mut updated_commitments = self.pcd_commitment.clone();
+        updated_commitments.update_with_value(&self.commited_in, key, new_value)?;
 
         // Update merkle tree
-        let merkle_tree = self.pcd_commitment.create_merkle_tree()?;
+        let merkle_tree = updated_commitments.create_merkle_tree()?;
 
         // Update state_id
         self.state_id = merkle_tree.root().ok_or_else(|| anyhow::Error::msg("Invalid merkle tree"))?;
+
+        // Everything is ok, we can update the state
+        self.pcd_commitment = updated_commitments;
  
         Ok(())
     }
@@ -139,7 +133,7 @@ impl ProcessState {
 
         // TODO check that it matches what we have in the commitment here or somewhere else?
 
-        let updated_member = Member::new(serde_json::from_value(updated_addresses.clone())?);
+        let updated_member = Member::new(from_reader(updated_addresses.as_slice())?);
         let previous_member = Member::new(previous_addresses);
 
         let members = if previous_member.get_addresses().is_empty() {
@@ -171,7 +165,7 @@ impl ProcessState {
             if self.pcd_commitment.contains_key(PAIREDADDRESSES) { 
                 if let Some(prev_state) = previous_state {
                     let prev_paired_addresses = prev_state.public_data.get(PAIREDADDRESSES).ok_or(anyhow::Error::msg("Missing pairedAddresses"))?;
-                    let paired_addresses = extract_paired_addresses(prev_paired_addresses)?;
+                    let paired_addresses = from_reader(prev_paired_addresses.as_slice())?;
                     return self.handle_pairing(pairing_role.clone(), paired_addresses);    
                 } else {
                     // We are in a creation