diff --git a/rln/rln.go b/rln/rln.go
index 0b423fe..bc5d617 100644
--- a/rln/rln.go
+++ b/rln/rln.go
@@ -13,14 +13,22 @@ type RLN struct {
 	ptr *C.RLN_Bn256
 }
 
+func New(depth int, parameters []byte) *RLN {
+	r := &RLN{}
+
+	buf := toBuffer(parameters)
+	C.new_circuit_from_params(C.ulong(depth), &buf, &r.ptr)
+
+	return r
+}
+
 func (r *RLN) Hash(input []byte) []byte {
 	size := int(unsafe.Sizeof(C.Buffer{}))
-
-	size = int(unsafe.Sizeof(C.Buffer{}))
 	in := (*C.Buffer)(C.malloc(C.size_t(size)))
+	*in = toBuffer(input)
 
 	out := (*C.Buffer)(C.malloc(C.size_t(size)))
-	C.hash(r.ptr, in, size, out)
+	C.hash(r.ptr, in, &in.len, out)
 
 	return C.GoBytes(unsafe.Pointer(out.ptr), C.int(out.len))
 }
diff --git a/rln/rln_test.go b/rln/rln_test.go
index 681f6e4..be1cd0e 100644
--- a/rln/rln_test.go
+++ b/rln/rln_test.go
@@ -1,8 +1,10 @@
 package rln
 
-import "testing"
+import (
+	"testing"
+)
 
 func TestHash(t *testing.T) {
-	rln := &RLN{}
+	rln := New(0, []byte{})
 	rln.Hash([]byte{1, 2, 3})
 }