diff --git a/pallets/exodus/Cargo.toml b/pallets/exodus/Cargo.toml
index 6d0de06..800b5e5 100644
--- a/pallets/exodus/Cargo.toml
+++ b/pallets/exodus/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "ghost-exodus"
-version = "0.1.4"
+version = "0.1.5"
 description = "Threshold signature generation with DKG included"
 license.workspace = true
 authors.workspace = true
diff --git a/pallets/exodus/src/lib.rs b/pallets/exodus/src/lib.rs
index 0489445..3fc105a 100644
--- a/pallets/exodus/src/lib.rs
+++ b/pallets/exodus/src/lib.rs
@@ -2769,6 +2769,10 @@ impl<T: Config> Pallet<T> {
             return Err(InvalidTransaction::Stale);
         }
 
+        if Round0Packages::<T>::contains_key(&network_curve, &authority_index) {
+            return Err(InvalidTransaction::Stale);
+        }
+
         let authorities = QualificationAuthorities::<T>::get(&network_curve);
         let authority = authorities.get(authority_index as usize)
             .ok_or(InvalidTransaction::BadSigner)?;
@@ -2836,6 +2840,10 @@ impl<T: Config> Pallet<T> {
             return Err(InvalidTransaction::Stale);
         }
 
+        if Round1Packages::<T>::get(&network_curve).contains(authority_index) {
+            return Err(InvalidTransaction::Stale);
+        }
+
         let authority = authorities
             .get(authority_index as usize)
             .ok_or(InvalidTransaction::BadSigner)?;
@@ -2915,6 +2923,10 @@ impl<T: Config> Pallet<T> {
             return Err(InvalidTransaction::Stale);
         }
 
+        if Round2Packages::<T>::get(&network_curve).contains(authority_index) {
+            return Err(InvalidTransaction::Stale);
+        }
+
         let authorities = QualificationAuthorities::<T>::get(&network_curve);
         let authority = authorities.get(authority_index as usize)
             .ok_or(InvalidTransaction::BadSigner)?;
@@ -2985,6 +2997,10 @@ impl<T: Config> Pallet<T> {
             return Err(InvalidTransaction::Stale);
         }
 
+        if Complaints::<T>::get(&network_curve).contains_key(&authority_index) {
+            return Err(InvalidTransaction::Stale);
+        }
+
         let authorities = QualificationAuthorities::<T>::get(&network_curve);
         let authority = authorities
             .get(authority_index as usize)
@@ -3067,6 +3083,10 @@ impl<T: Config> Pallet<T> {
             return Err(InvalidTransaction::Stale);
         }
 
+        if Justifications::<T>::get(&network_curve).contains_key(&authority_index) {
+            return Err(InvalidTransaction::Stale);
+        }
+
         let authorities = QualificationAuthorities::<T>::get(&network_curve);
         let authority = authorities.get(authority_index as usize)
             .ok_or(InvalidTransaction::BadSigner)?;
@@ -3129,6 +3149,13 @@ impl<T: Config> Pallet<T> {
             return Err(InvalidTransaction::Stale);
         }
 
+        if VerifyingKeyConsensus::<T>::get(&network_curve, &package_dkg_index)
+            .state
+            .participants
+            .contains(authority_index) {
+                return Err(InvalidTransaction::Stale);
+            }
+
         let authorities = QualificationAuthorities::<T>::get(&network_curve);
         let authority = authorities.get(authority_index as usize)
             .ok_or(InvalidTransaction::BadSigner)?;
@@ -3195,6 +3222,11 @@ impl<T: Config> Pallet<T> {
             return Err(InvalidTransaction::Stale);
         }
 
+        if VerifyingSharesParticipants::<T>::get(&network_curve, package_dkg_index)
+            .contains(authority_index) {
+                return Err(InvalidTransaction::Stale);
+            }
+
         let authorities = QualificationAuthorities::<T>::get(&network_curve);
         let authority = authorities.get(authority_index as usize)
             .ok_or(InvalidTransaction::BadSigner)?;
@@ -3263,15 +3295,6 @@ impl<T: Config> Pallet<T> {
             return Err(InvalidTransaction::Stale);
         }
 
-        let authorities = ActiveAuthorities::<T>::get(&network_curve);
-        let authority = authorities.get(authority_index as usize)
-            .ok_or(InvalidTransaction::BadSigner)?;
-
-        let encoded_package = exodus_package.encode();
-        if !authority.verify(&encoded_package, signature) {
-            return Err(InvalidTransaction::BadProof);
-        }
-
         let exodus_request =
             ExodusRequests::<T>::get((&network_curve, exodus_context))
                 .ok_or(InvalidTransaction::BadProof)?;
@@ -3282,6 +3305,22 @@ impl<T: Config> Pallet<T> {
                 None => exodus_request.next_roast_session,
             };
 
+        if NonceCommitments::<T>::contains_key(
+            (exodus_context, roast_session),
+            authority_index
+        ) {
+            return Err(InvalidTransaction::Stale);
+        }
+
+        let authorities = ActiveAuthorities::<T>::get(&network_curve);
+        let authority = authorities.get(authority_index as usize)
+            .ok_or(InvalidTransaction::BadSigner)?;
+
+        let encoded_package = exodus_package.encode();
+        if !authority.verify(&encoded_package, signature) {
+            return Err(InvalidTransaction::BadProof);
+        }
+
         Ok((exodus_request, roast_session))
     }
 
@@ -3331,6 +3370,22 @@ impl<T: Config> Pallet<T> {
             return Err(InvalidTransaction::Stale);
         }
 
+        let roast_session =
+            RoastSessions::<T>::get(exodus_context, &authority_index)
+                .ok_or(InvalidTransaction::BadProof)?;
+
+        let roast_state = RoastSessionStates::<T>::get(&exodus_context, &roast_session);
+        let is_nonce_committer = roast_state.nonce_committers.contains(authority_index);
+        let is_group_committer = roast_state.group_committers.contains(authority_index);
+        let is_partial_signer = roast_state.partial_signers.contains(authority_index);
+
+        let threshold_reached = roast_state.nonce_committers == roast_state.group_committers;
+        let already_committed = !threshold_reached || is_group_committer;
+
+        if !is_nonce_committer || !already_committed || is_partial_signer {
+            return Err(InvalidTransaction::Stale);
+        }
+
         let authorities = ActiveAuthorities::<T>::get(&network_curve);
         let authority = authorities.get(authority_index as usize)
             .ok_or(InvalidTransaction::BadSigner)?;
@@ -3340,8 +3395,7 @@ impl<T: Config> Pallet<T> {
             return Err(InvalidTransaction::BadProof);
         }
 
-        RoastSessions::<T>::get(exodus_context, &authority_index)
-            .ok_or(InvalidTransaction::BadProof)
+        Ok(roast_session)
     }
 
     fn validate_exodus_signature_share_size_and_get_metadata<'a>(
@@ -3395,6 +3449,19 @@ impl<T: Config> Pallet<T> {
             return Err(InvalidTransaction::Stale);
         }
 
+        let roast_session =
+            RoastSessions::<T>::get(exodus_context, &authority_index)
+                .ok_or(InvalidTransaction::BadProof)?;
+
+        let roast_state = RoastSessionStates::<T>::get(&exodus_context, &roast_session);
+        let is_nonce_committer = roast_state.nonce_committers.contains(authority_index);
+        let is_group_committer = roast_state.group_committers.contains(authority_index);
+        let is_partial_signer = roast_state.partial_signers.contains(authority_index);
+
+        if !is_nonce_committer || !is_group_committer || is_partial_signer {
+            return Err(InvalidTransaction::Stale);
+        }
+
         let authorities = ActiveAuthorities::<T>::get(&network_curve);
         let authority = authorities.get(authority_index as usize)
             .ok_or(InvalidTransaction::BadSigner)?;
@@ -3404,10 +3471,6 @@ impl<T: Config> Pallet<T> {
             return Err(InvalidTransaction::BadProof);
         }
 
-        let roast_session =
-            RoastSessions::<T>::get(exodus_context, &authority_index)
-                .ok_or(InvalidTransaction::BadProof)?;
-
         Ok((roast_session, active_state.get_dkg_index()))
     }