diff --git a/src/constraints.rs b/src/constraints.rs
new file mode 100644
index 0000000..8116548
--- /dev/null
+++ b/src/constraints.rs
@@ -0,0 +1,22 @@
+use ark_r1cs_std::prelude::*;
+use ark_relations::r1cs::SynthesisError;
+
+use crate::BlindSignatureScheme;
+use ark_ff::PrimeField;
+use arkworks_r1cs_gadgets::poseidon::PoseidonGadget;
+
+pub trait BlindSigVerifyGadget<S: BlindSignatureScheme, ConstraintF: PrimeField> {
+    type ParametersVar: AllocVar<S::Parameters, ConstraintF> + Clone;
+    type PublicKeyVar: AllocVar<S::PublicKey, ConstraintF> + Clone;
+    type SignatureVar: AllocVar<S::Signature, ConstraintF> + Clone;
+    type Msg;
+    type MsgVar: AllocVar<Self::Msg, ConstraintF> + Clone;
+
+    fn verify(
+        parameters: &Self::ParametersVar,
+        poseidon_hash: &PoseidonGadget<ConstraintF>,
+        m: &Self::MsgVar,
+        s: &Self::SignatureVar,
+        q: &Self::PublicKeyVar,
+    ) -> Result<Boolean<ConstraintF>, SynthesisError>;
+}
diff --git a/src/lib.rs b/src/lib.rs
index 073a8ba..5a7d97d 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1,5 +1,8 @@
 use ark_std::rand::Rng;
 
+// #[cfg(feature="r1cs")]
+pub mod constraints;
+
 pub mod mala_nezhadansari;
 pub mod schnorr_blind;
 
@@ -14,6 +17,7 @@ pub trait BlindSignatureScheme {
     type PointAffine;
     type SecretKey;
     type PublicKey;
+    // type Msg;
     type BlindedSignature;
     type Signature;
     type UserSecretData;