diff --git a/taiga_halo2/src/circuit/blake2s.rs b/taiga_halo2/src/circuit/blake2s.rs
index 91d7a5f0..429a2dd6 100644
--- a/taiga_halo2/src/circuit/blake2s.rs
+++ b/taiga_halo2/src/circuit/blake2s.rs
@@ -431,7 +431,7 @@ impl<F: PrimeField> Blake2sChip<F> {
     pub fn encode_result(
         &self,
         layouter: &mut impl Layouter<F>,
-        ret: &Vec<Blake2sWord<F>>,
+        ret: &[Blake2sWord<F>],
     ) -> Result<[AssignedCell<F, F>; 2], Error> {
         let mut fields = vec![];
         assert_eq!(ret.len(), 8);
@@ -976,7 +976,7 @@ impl<F: PrimeField> Blake2sWord<F> {
         })
     }
 
-    pub fn word_rotate(bits: &Vec<AssignedCell<F, F>>, by: usize) -> Vec<AssignedCell<F, F>> {
+    pub fn word_rotate(bits: &[AssignedCell<F, F>], by: usize) -> Vec<AssignedCell<F, F>> {
         assert!(bits.len() == 32);
         let by = by % 32;
         bits.iter()
diff --git a/taiga_halo2/src/circuit/vp_circuit.rs b/taiga_halo2/src/circuit/vp_circuit.rs
index 3449d9e6..7615ceb1 100644
--- a/taiga_halo2/src/circuit/vp_circuit.rs
+++ b/taiga_halo2/src/circuit/vp_circuit.rs
@@ -147,8 +147,7 @@ impl Encoder for ValidityPredicatePublicInputs {
 impl<'a> Decoder<'a> for ValidityPredicatePublicInputs {
     fn decode(term: Term<'a>) -> NifResult<Self> {
         let val: Vec<pallas::Base> = Decoder::decode(term)?;
-        val.try_into()
-            .map_err(|_e| rustler::Error::Atom("failure to decode"))
+        Ok(val.into())
     }
 }
 
diff --git a/taiga_halo2/src/resource_encryption.rs b/taiga_halo2/src/resource_encryption.rs
index 7e49a710..79427e4a 100644
--- a/taiga_halo2/src/resource_encryption.rs
+++ b/taiga_halo2/src/resource_encryption.rs
@@ -132,8 +132,8 @@ impl ResourcePlaintext {
         self.0.to_vec()
     }
 
-    pub fn padding(msg: &Vec<pallas::Base>) -> Self {
-        let mut plaintext = msg.clone();
+    pub fn padding(msg: &[pallas::Base]) -> Self {
+        let mut plaintext = msg.to_owned();
         let padding = std::iter::repeat(pallas::Base::zero())
             .take(RESOURCE_ENCRYPTION_PLAINTEXT_NUM - msg.len());
         plaintext.extend(padding);
@@ -183,7 +183,7 @@ fn test_halo2_resource_encryption() {
         pallas::Base::one(),
         pallas::Base::one(),
     ];
-    let plaintext = ResourcePlaintext::padding(&message.to_vec());
+    let plaintext = ResourcePlaintext::padding(message.as_ref());
     let encrypt_nonce = pallas::Base::from_u128(23333u128);
 
     // Encryption