diff --git a/bindings/cashu-ffi/src/cashu.udl b/bindings/cashu-ffi/src/cashu.udl
index e128c0e4..52a34de9 100644
--- a/bindings/cashu-ffi/src/cashu.udl
+++ b/bindings/cashu-ffi/src/cashu.udl
@@ -27,6 +27,10 @@ interface Secret {
 	sequence<u8> as_bytes();	
 };
 
+interface Id {
+    [Throws=CashuError]
+	constructor(string id);
+};
 
 interface PublicKey {
     [Throws=CashuError, Name=from_hex]
@@ -48,26 +52,26 @@ interface BlindedMessage {
 };
 
 interface Proof {
-	constructor(Amount amount, Secret secret, PublicKey c, string? id);
+	constructor(Amount amount, Secret secret, PublicKey c, Id? id);
 	Amount amount();
 	Secret secret();
 	PublicKey c();
-	string? id();
+ 	Id? id();
 };
 
 interface BlindedSignature {
-	constructor(string id, Amount amount, PublicKey c);
-	string id();
+	constructor(Id id, Amount amount, PublicKey c);
+	Id id();
 	Amount amount();
 	PublicKey c();
 };
 
 interface MintProof {
-	constructor(Amount? amount, Secret secret, PublicKey? c, string? id);
+	constructor(Amount? amount, Secret secret, PublicKey? c, Id? id);
 	Amount? amount();
 	Secret secret();
 	PublicKey? c();
-	string? id();
+	Id? id();
 	
 };
 
@@ -116,8 +120,8 @@ interface Keys {
 };
 
 interface KeySet {
-	constructor(string id, Keys keys);
-	string id();
+	constructor(Id id, Keys keys);
+	Id id();
 	Keys keys();
 };
 
@@ -127,8 +131,8 @@ interface MintKeySet {
 };
 
 interface KeySetResponse {
-	constructor(sequence<string> keyset_ids);
-	sequence<string> keyset_ids();
+	constructor(sequence<Id> keyset_ids);
+	sequence<Id> keyset_ids();
 };
 
 interface RequestMintResponse {
diff --git a/bindings/cashu-ffi/src/error.rs b/bindings/cashu-ffi/src/error.rs
index 1f3c4461..c545a111 100644
--- a/bindings/cashu-ffi/src/error.rs
+++ b/bindings/cashu-ffi/src/error.rs
@@ -48,3 +48,11 @@ impl From<ParseOrSemanticError> for CashuError {
         }
     }
 }
+
+impl From<cashu::nuts::nut02::Error> for CashuError {
+    fn from(err: cashu::nuts::nut02::Error) -> Self {
+        Self::Generic {
+            err: "Nut 2 error".to_string(),
+        }
+    }
+}
diff --git a/bindings/cashu-ffi/src/lib.rs b/bindings/cashu-ffi/src/lib.rs
index 247755de..926b74fc 100644
--- a/bindings/cashu-ffi/src/lib.rs
+++ b/bindings/cashu-ffi/src/lib.rs
@@ -14,7 +14,7 @@ mod ffi {
     pub use crate::nuts::nut01::keys::Keys;
     pub use crate::nuts::nut01::public_key::PublicKey;
     pub use crate::nuts::nut01::secret_key::SecretKey;
-    pub use crate::nuts::nut02::{KeySet, KeySetResponse, MintKeySet};
+    pub use crate::nuts::nut02::{Id, KeySet, KeySetResponse, MintKeySet};
     pub use crate::nuts::nut03::RequestMintResponse;
     pub use crate::nuts::nut04::{MintRequest, PostMintResponse};
     pub use crate::nuts::nut05::{
diff --git a/bindings/cashu-ffi/src/nuts/nut00/blinded_signature.rs b/bindings/cashu-ffi/src/nuts/nut00/blinded_signature.rs
index 6667a2a4..ea195a3b 100644
--- a/bindings/cashu-ffi/src/nuts/nut00/blinded_signature.rs
+++ b/bindings/cashu-ffi/src/nuts/nut00/blinded_signature.rs
@@ -4,6 +4,7 @@ use std::sync::Arc;
 use cashu::nuts::nut00::BlindedSignature as BlindedSignatureSdk;
 
 use crate::Amount;
+use crate::Id;
 use crate::PublicKey;
 
 pub struct BlindedSignature {
@@ -11,18 +12,18 @@ pub struct BlindedSignature {
 }
 
 impl BlindedSignature {
-    pub fn new(id: String, amount: Arc<Amount>, c: Arc<PublicKey>) -> Self {
+    pub fn new(id: Arc<Id>, amount: Arc<Amount>, c: Arc<PublicKey>) -> Self {
         Self {
             inner: BlindedSignatureSdk {
-                id,
+                id: *id.as_ref().deref(),
                 amount: *amount.as_ref().deref(),
                 c: c.as_ref().into(),
             },
         }
     }
 
-    pub fn id(&self) -> String {
-        self.inner.id.clone()
+    pub fn id(&self) -> Arc<Id> {
+        Arc::new(self.inner.id.clone().into())
     }
 
     pub fn amount(&self) -> Arc<Amount> {
diff --git a/bindings/cashu-ffi/src/nuts/nut00/proof.rs b/bindings/cashu-ffi/src/nuts/nut00/proof.rs
index 2a3ab6a1..da10eb45 100644
--- a/bindings/cashu-ffi/src/nuts/nut00/proof.rs
+++ b/bindings/cashu-ffi/src/nuts/nut00/proof.rs
@@ -2,7 +2,7 @@ use std::{ops::Deref, sync::Arc};
 
 use cashu::nuts::nut00::Proof as ProofSdk;
 
-use crate::{types::Secret, Amount, PublicKey};
+use crate::{types::Secret, Amount, Id, PublicKey};
 
 pub struct Proof {
     inner: ProofSdk,
@@ -20,14 +20,14 @@ impl Proof {
         amount: Arc<Amount>,
         secret: Arc<Secret>,
         c: Arc<PublicKey>,
-        id: Option<String>,
+        id: Option<Arc<Id>>,
     ) -> Self {
         Self {
             inner: ProofSdk {
                 amount: *amount.as_ref().deref(),
                 secret: secret.as_ref().deref().clone(),
                 c: c.as_ref().deref().clone(),
-                id,
+                id: id.map(|id| id.as_ref().deref().clone()),
             },
         }
     }
@@ -44,8 +44,8 @@ impl Proof {
         Arc::new(self.inner.c.clone().into())
     }
 
-    pub fn id(&self) -> Option<String> {
-        self.inner.id.clone()
+    pub fn id(&self) -> Option<Arc<Id>> {
+        self.inner.id.clone().map(|id| Arc::new(id.into()))
     }
 }
 
@@ -55,7 +55,7 @@ impl From<&Proof> for ProofSdk {
             amount: *proof.amount().as_ref().deref(),
             secret: proof.secret().as_ref().deref().clone(),
             c: proof.c().deref().into(),
-            id: proof.id(),
+            id: proof.id().map(|id| id.as_ref().deref().clone()),
         }
     }
 }
@@ -74,6 +74,7 @@ pub mod mint {
 
     use crate::types::Secret;
     use crate::Amount;
+    use crate::Id;
     use crate::PublicKey;
 
     pub struct Proof {
@@ -92,14 +93,14 @@ pub mod mint {
             amount: Option<Arc<Amount>>,
             secret: Arc<Secret>,
             c: Option<Arc<PublicKey>>,
-            id: Option<String>,
+            id: Option<Arc<Id>>,
         ) -> Self {
             Self {
                 inner: ProofSdk {
                     amount: amount.map(|a| *a.as_ref().deref()),
                     secret: secret.as_ref().deref().clone(),
                     c: c.map(|c| c.as_ref().into()),
-                    id,
+                    id: id.map(|id| id.as_ref().deref().clone()),
                 },
             }
         }
@@ -116,8 +117,8 @@ pub mod mint {
             self.inner.c.clone().map(|c| Arc::new(c.into()))
         }
 
-        pub fn id(&self) -> Option<String> {
-            self.inner.id.clone()
+        pub fn id(&self) -> Option<Arc<Id>> {
+            self.inner.id.clone().map(|id| Arc::new(id.into()))
         }
     }
 
diff --git a/bindings/cashu-ffi/src/nuts/nut02/key_set.rs b/bindings/cashu-ffi/src/nuts/nut02/key_set.rs
index 239a61e2..1b96a947 100644
--- a/bindings/cashu-ffi/src/nuts/nut02/key_set.rs
+++ b/bindings/cashu-ffi/src/nuts/nut02/key_set.rs
@@ -1,12 +1,43 @@
-use std::collections::HashSet;
 use std::ops::Deref;
 use std::sync::Arc;
 
+use cashu::nuts::nut02::Id as IdSdk;
 use cashu::nuts::nut02::KeySet as KeySetSdk;
 use cashu::nuts::nut02::Response;
 
+use crate::error::Result;
 use crate::nuts::nut01::keys::Keys;
 
+pub struct Id {
+    inner: IdSdk,
+}
+
+impl Deref for Id {
+    type Target = IdSdk;
+    fn deref(&self) -> &Self::Target {
+        &self.inner
+    }
+}
+impl Id {
+    pub fn new(id: String) -> Result<Self> {
+        Ok(Self {
+            inner: IdSdk::try_from_base64(&id)?,
+        })
+    }
+}
+
+impl From<IdSdk> for Id {
+    fn from(inner: IdSdk) -> Id {
+        Id { inner }
+    }
+}
+
+impl From<Id> for IdSdk {
+    fn from(id: Id) -> IdSdk {
+        id.inner
+    }
+}
+
 pub struct KeySet {
     inner: KeySetSdk,
 }
@@ -19,17 +50,17 @@ impl Deref for KeySet {
 }
 
 impl KeySet {
-    pub fn new(id: String, keys: Arc<Keys>) -> Self {
+    pub fn new(id: Arc<Id>, keys: Arc<Keys>) -> Self {
         Self {
             inner: KeySetSdk {
-                id,
+                id: id.as_ref().deref().clone(),
                 keys: keys.as_ref().deref().clone(),
             },
         }
     }
 
-    pub fn id(&self) -> String {
-        self.inner.id.clone()
+    pub fn id(&self) -> Arc<Id> {
+        Arc::new(self.inner.id.clone().into())
     }
 
     pub fn keys(&self) -> Arc<Keys> {
@@ -48,15 +79,20 @@ pub struct KeySetResponse {
 }
 
 impl KeySetResponse {
-    pub fn new(keyset_ids: Vec<String>) -> Self {
-        let keysets = HashSet::from_iter(keyset_ids);
+    pub fn new(keyset_ids: Vec<Arc<Id>>) -> Self {
+        let keysets = keyset_ids.into_iter().map(|id| id.inner).collect();
         Self {
             inner: Response { keysets },
         }
     }
 
-    pub fn keyset_ids(&self) -> Vec<String> {
-        self.inner.clone().keysets.into_iter().collect()
+    pub fn keyset_ids(&self) -> Vec<Arc<Id>> {
+        self.inner
+            .clone()
+            .keysets
+            .into_iter()
+            .map(|id| Arc::new(id.into()))
+            .collect()
     }
 }
 
diff --git a/bindings/cashu-ffi/src/nuts/nut02/mod.rs b/bindings/cashu-ffi/src/nuts/nut02/mod.rs
index a03ce11a..7836f6e2 100644
--- a/bindings/cashu-ffi/src/nuts/nut02/mod.rs
+++ b/bindings/cashu-ffi/src/nuts/nut02/mod.rs
@@ -1,5 +1,5 @@
 pub mod key_set;
 pub mod mint_keyset;
 
-pub use key_set::{KeySet, KeySetResponse};
+pub use key_set::{Id, KeySet, KeySetResponse};
 pub use mint_keyset::MintKeySet;