diff --git a/src/device.rs b/src/device.rs
index 5e491b9..4c49cf9 100644
--- a/src/device.rs
+++ b/src/device.rs
@@ -1,10 +1,9 @@
-use serde_json::Value;
 use serde::{Deserialize, Serialize};
 use tsify::Tsify;
 use uuid::Uuid;
 use wasm_bindgen::prelude::*;
 
-use sp_client::{silentpayments::utils::SilentPaymentAddress, spclient::SpWallet};
+use sp_client::spclient::SpWallet;
 
 use crate::pcd::Member;
 
@@ -13,8 +12,7 @@ use crate::pcd::Member;
 pub struct Device {
     sp_wallet: SpWallet,
     pairing_process_uuid: Option<String>,
-    paired_devices: Vec<String>, // map an address to the pairing process
-    latest_known_state: Value
+    paired_member: Option<Member>,
 }
 
 impl Device {
@@ -22,8 +20,7 @@ impl Device {
         Self {
             sp_wallet,
             pairing_process_uuid: None,
-            paired_devices: vec![],
-            latest_known_state: Value::Null
+            paired_member: None,
         }
     }
 
@@ -43,33 +40,12 @@ impl Device {
         self.pairing_process_uuid.clone()
     }
 
-    pub fn set_process_uuid(&mut self, uuid: Uuid) {
+    pub fn pair(&mut self, uuid: Uuid, member: Member) {
         self.pairing_process_uuid = Some(uuid.to_string());
+        self.paired_member = Some(member);
     }
 
-    pub fn get_paired_devices(&self) -> Vec<String> {
-        self.paired_devices.clone()
-    }
-
-    pub fn push_paired_device(&mut self, new_device_address: SilentPaymentAddress) {
-        self.paired_devices.push(new_device_address.into())
-    }
-
-    pub fn to_member(&self) -> anyhow::Result<Member> {
-        if !self.is_linked() {
-            return Err(anyhow::Error::msg("device is not linked"));
-        }
-
-        let member = self.latest_known_state.as_object().unwrap().get("member").unwrap().clone();
-        let res: Member = serde_json::from_value(member)?;
-        Ok(res)
-    }
-
-    pub fn get_latest_state(&self) -> Value {
-        self.latest_known_state.clone()
-    }
-
-    pub fn update_latest_state(&mut self, update: Value) {
-        self.latest_known_state = update;
+    pub fn to_member(&self) -> Option<Member> {
+        self.paired_member.clone()
     }
 }
\ No newline at end of file
diff --git a/src/pcd.rs b/src/pcd.rs
index 77f2626..97e57f2 100644
--- a/src/pcd.rs
+++ b/src/pcd.rs
@@ -1,4 +1,4 @@
-use std::str::FromStr;
+use std::{collections::{HashMap, HashSet}, str::FromStr};
 use anyhow::{Result, Error};
 
 use aes_gcm::{aead::{Aead, Payload}, AeadCore, Aes256Gcm, KeyInit};
@@ -11,47 +11,38 @@ use tsify::Tsify;
 
 use crate::crypto::AAD;
 
-#[derive(Debug, Clone, Copy, Serialize, Deserialize, Tsify, PartialEq, Eq, Hash, PartialOrd)]
-pub enum Role {
-    User,
-    Manager,
-    Admin,
-}
-
 #[derive(Debug, Clone, PartialEq, Eq, Hash, Serialize, Deserialize, Tsify)]
 #[tsify(into_wasm_abi, from_wasm_abi)]
 pub struct Member {
-    nym: String,
-    sp_address_a: String,
-    sp_address_b: String,
-    role: Role,
+    sp_addresses: Vec<String>
 }
 
 impl Member {
     pub fn new(
-        nym: String,
-        sp_address_a: SilentPaymentAddress,
-        sp_address_b: SilentPaymentAddress,
-        role: Role,
-    ) -> Self {
-        Self {
-            nym,
-            sp_address_a: sp_address_a.into(),
-            sp_address_b: sp_address_b.into(),
-            role,
+        sp_addresses: Vec<SilentPaymentAddress>,
+    ) -> Result<Self> {
+        if sp_addresses.is_empty() {
+            return Err(Error::msg("empty address set"));
         }
+
+        let mut seen = HashSet::new();
+        for s in sp_addresses.iter() {
+            if !seen.insert(s.clone()) {
+                return Err(Error::msg("Duplicate addresses found"));
+            }
+        }
+
+        let res: Vec<String> = sp_addresses.iter()
+            .map(|a| Into::<String>::into(*a))
+            .collect();
+
+        Ok(Self {
+            sp_addresses: res
+        })
     }
 
-    pub fn get_nym(&self) -> String {
-        self.nym.clone()
-    }
-
-    pub fn get_addresses(&self) -> (String, String) {
-        (self.sp_address_a.clone(), self.sp_address_b.clone())
-    }
-
-    pub fn get_role(&self) -> Role {
-        self.role
+    pub fn get_addresses(&self) -> Vec<String> {
+        self.sp_addresses.clone()
     }
 }
 
@@ -145,3 +136,48 @@ pub trait Pcd<'a>: Serialize + Deserialize<'a> {
 }
 
 impl Pcd<'_> for Value {}
+
+#[derive(Debug, Clone, Serialize, Deserialize, Tsify)]
+#[tsify(into_wasm_abi, from_wasm_abi)]
+pub struct ValidationRule {
+    quorum: f32, // Must be >= 0.0, <= 1.0, 0.0 means reading right
+    pub fields: Vec<String>, // Which fields are concerned by this rule
+    min_sig_member: f32, // Must be >= 0.0, <= 1.0, does each member need to sign with all it's devices?
+}
+
+impl ValidationRule {
+    pub fn new(quorum: f32, fields: Vec<String>, min_sig_member: f32) -> Result<Self> {
+        if quorum < 0.0 || quorum > 1.0 {
+            return Err(Error::msg("quorum must be 0.0 < quorum <= 1.0"));
+        }
+
+        if min_sig_member < 0.0 || min_sig_member > 1.0 {
+            return Err(Error::msg("min_signatures_member must be 0.0 < min_signatures_member <= 1.0"));
+        }
+
+        if fields.is_empty() {
+            return Err(Error::msg("Fields can't be empty"));
+        }
+
+        let res = Self {
+            quorum,
+            fields,
+            min_sig_member,
+        };
+
+        Ok(res)
+    }
+}
+
+#[derive(Debug, Clone, Serialize, Deserialize, Tsify)]
+#[tsify(into_wasm_abi, from_wasm_abi)]
+pub struct RoleDefinition {
+    pub members: Vec<Member>,
+    pub validation_rules: Vec<ValidationRule>,
+}
+
+// #[derive(Debug, Clone, Serialize, Deserialize, Tsify)]
+// #[tsify(into_wasm_abi, from_wasm_abi)]
+// pub struct Roles {
+//     pub roles: HashMap<String, RoleDefinition>
+// }
diff --git a/src/prd.rs b/src/prd.rs
index b51570d..9066900 100644
--- a/src/prd.rs
+++ b/src/prd.rs
@@ -1,3 +1,4 @@
+use std::collections::HashSet;
 use std::str::FromStr;
 
 use anyhow::{Result, Error};
@@ -5,6 +6,7 @@ use serde::{Serialize, Deserialize};
 
 use serde_json::{Map, Value};
 use sp_client::bitcoin::secp256k1::SecretKey;
+use sp_client::bitcoin::XOnlyPublicKey;
 use sp_client::silentpayments::utils::SilentPaymentAddress;
 use sp_client::spclient::SpWallet;
 use sp_client::bitcoin::secp256k1::schnorr::Signature;
@@ -77,8 +79,7 @@ impl AnkValidationNoHash {
 pub struct ValidationToken {
     member: Member,
     message: [u8; 32], 
-    sig_a: Signature,
-    sig_b: Signature, // User must sign with its 2 paired devices
+    sigs: Vec<Signature>, // User must sign with the requested number of devices
 }
 
 sha256t_hash_newtype! {
@@ -146,13 +147,22 @@ impl Prd {
         // check that the proof is consistent
         let sender: Member = serde_json::from_str(&prd.sender)?;
         if let Some(proof) = prd.proof {
-            // take the 2 spending keys in sender
-            let (address_a, address_b) = sender.get_addresses();
-            let spend_key_a = <SilentPaymentAddress>::try_from(address_a)?.get_spend_key().x_only_public_key().0;
-            let spend_key_b = <SilentPaymentAddress>::try_from(address_b)?.get_spend_key().x_only_public_key().0;
-            // The key in proof must be one of the 2 sender keys
+            // take the spending keys in sender
+            let addresses = sender.get_addresses();
+            let mut spend_keys: Vec<XOnlyPublicKey> = vec![];
+            for address in addresses {
+                spend_keys.push(<SilentPaymentAddress>::try_from(address)?.get_spend_key().x_only_public_key().0);
+            }
+            // The key in proof must be one of the sender keys
             let proof_key = proof.get_key();
-            if spend_key_a != proof_key && spend_key_b != proof_key {
+            let mut known_key = false;
+            for key in spend_keys {
+                if key == proof_key {
+                    known_key = true;
+                    break;
+                }
+            }
+            if !known_key {
                 return Err(anyhow::Error::msg("Proof signed with an unknown key"));
             }
             proof.verify()?;    
@@ -168,7 +178,7 @@ impl Prd {
         Ok(())
     }
 
-    pub fn filter_keys(&mut self, to_keep: Vec<String>) {
+    pub fn filter_keys(&mut self, to_keep: HashSet<String>) {
         let current_keys = self.keys.clone();
         let filtered_keys: Map<String, Value> = current_keys.into_iter()
             .filter(|(field, _)| to_keep.contains(field))
diff --git a/src/process.rs b/src/process.rs
index a42623f..2ad347b 100644
--- a/src/process.rs
+++ b/src/process.rs
@@ -1,59 +1,35 @@
-use std::str::FromStr;
+use std::collections::HashMap;
+
+use anyhow::{Error, Result};
 
 use serde::{Deserialize, Serialize};
-use serde_json::Value;
-use sp_client::{bitcoin::OutPoint, silentpayments::utils::SilentPaymentAddress};
+use serde_json::{Map, Value};
+use sp_client::bitcoin::OutPoint;
 use tsify::Tsify;
 use uuid::Uuid;
 use wasm_bindgen::prelude::*;
 
-use crate::pcd::Role;
-
-#[derive(Debug, Clone, Serialize, Deserialize, Tsify)]
-#[tsify(into_wasm_abi, from_wasm_abi)]
-pub struct ValidationRules {
-    quorum: f32, // Must be > 0.0, <= 1.0
-    min_permission: Role, // Only users with at least that Role can send a token
-    min_signatures_member: f32, // Must be > 0.0, <= 1.0, does each member need to sign with all it's devices?
-}
-
-impl ValidationRules {
-    pub fn new(quorum: f32, min_permission: Role, min_signatures_member: f32) -> Self {
-        Self {
-            quorum,
-            min_permission,
-            min_signatures_member,
-        }
-    }
-}
-
 #[derive(Debug, Clone, Serialize, Deserialize, Tsify)]
 #[tsify(into_wasm_abi, from_wasm_abi)]
 pub struct Process {
     pub uuid: String,
-    pub name: String,
-    pub validation_rules: ValidationRules,
     pub html: String,
     pub style: String,
     pub script: String,
-    pub init_state: Value,
+    pub init_state: Map<String, Value>,
     pub commited_in: OutPoint,
 }
 
 impl Process {
     pub fn new(
-        name: String,
-        validation_rules: ValidationRules,
         html: String,
         style: String,
         script: String,
-        init_state: Value,
+        init_state: Map<String, Value>,
         commited_in: OutPoint,
     ) -> Self {
         Self {
             uuid: Uuid::new_v4().to_string(),
-            name,
-            validation_rules,
             html,
             style,
             script,