diff --git a/babyjub/eddsa.go b/babyjub/eddsa.go
index 5870213..3093a4a 100644
--- a/babyjub/eddsa.go
+++ b/babyjub/eddsa.go
@@ -222,11 +222,13 @@ func (k *PrivateKey) SignPoseidon(msg *big.Int) *Signature {
 	r.Mod(r, SubOrder)
 	R8 := NewPoint().Mul(r, B8) // R8 = r * 8 * B
 	A := k.Public().Point()
+
 	hmInput := [poseidon.T]*big.Int{R8.X, R8.Y, A.X, A.Y, msg, big.NewInt(int64(0))}
 	hm, err := poseidon.PoseidonHash(hmInput) // hm = H1(8*R.x, 8*R.y, A.x, A.y, msg)
 	if err != nil {
 		panic(err)
 	}
+
 	S := new(big.Int).Lsh(k.Scalar().BigInt(), 3)
 	S = S.Mul(hm, S)
 	S.Add(r, S)
diff --git a/ff/util.go b/ff/util.go
new file mode 100644
index 0000000..501b6ae
--- /dev/null
+++ b/ff/util.go
@@ -0,0 +1,5 @@
+package ff
+
+func NewElement() *Element {
+	return &Element{}
+}
diff --git a/poseidon/poseidon.go b/poseidon/poseidon.go
index 79cd651..a5dc7b0 100644
--- a/poseidon/poseidon.go
+++ b/poseidon/poseidon.go
@@ -5,6 +5,7 @@ import (
 	"math/big"
 	"strconv"
 
+	"github.com/iden3/go-iden3-crypto/constants"
 	"github.com/iden3/go-iden3-crypto/ff"
 	"github.com/iden3/go-iden3-crypto/utils"
 	"golang.org/x/crypto/blake2b"
@@ -19,7 +20,11 @@ var constC []*ff.Element
 var constM [T][T]*ff.Element
 
 func Zero() *ff.Element {
-	return utils.NewElement().SetZero()
+	return ff.NewElement().SetZero()
+}
+
+func modQ(v *big.Int) {
+	v.Mod(v, constants.Q)
 }
 
 func init() {
@@ -32,7 +37,7 @@ func getPseudoRandom(seed string, n int) []*ff.Element {
 	hash := blake2b.Sum256([]byte(seed))
 	for i := 0; i < n; i++ {
 		hashBigInt := big.NewInt(int64(0))
-		res[i] = utils.NewElement().SetBigInt(utils.SetBigIntFromLEBytes(hashBigInt, hash[:]))
+		res[i] = ff.NewElement().SetBigInt(utils.SetBigIntFromLEBytes(hashBigInt, hash[:]))
 		hash = blake2b.Sum256(hash[:])
 	}
 	return res
@@ -57,7 +62,7 @@ func getMDS() [T][T]*ff.Element {
 	var m [T][T]*ff.Element
 	for i := 0; i < T; i++ {
 		for j := 0; j < T; j++ {
-			m[i][j] = utils.NewElement().Sub(cauchyMatrix[i], cauchyMatrix[T+j])
+			m[i][j] = ff.NewElement().Sub(cauchyMatrix[i], cauchyMatrix[T+j])
 			m[i][j].Inverse(m[i][j])
 		}
 	}
@@ -66,7 +71,7 @@ func getMDS() [T][T]*ff.Element {
 
 func checkAllDifferent(v []*ff.Element) bool {
 	for i := 0; i < len(v); i++ {
-		if v[i].Equal(utils.NewElement().SetZero()) {
+		if v[i].Equal(ff.NewElement().SetZero()) {
 			return false
 		}
 		for j := i + 1; j < len(v); j++ {
@@ -117,13 +122,14 @@ func mix(state [T]*ff.Element, newState [T]*ff.Element, m [T][T]*ff.Element) {
 }
 
 // PoseidonHash computes the Poseidon hash for the given inputs
-func PoseidonHash(inp [T]*ff.Element) (*ff.Element, error) {
-	if !utils.CheckElementArrayInField(inp[:]) {
+func PoseidonHash(inpBI [T]*big.Int) (*big.Int, error) {
+	if !utils.CheckBigIntArrayInField(inpBI[:]) {
 		return nil, errors.New("inputs values not inside Finite Field")
 	}
+	inp := utils.BigIntArrayToElementArray(inpBI[:])
 	state := [T]*ff.Element{}
 	for i := 0; i < T; i++ {
-		state[i] = utils.NewElement().Set(inp[i])
+		state[i] = ff.NewElement().Set(inp[i])
 	}
 
 	// ARK --> SBox --> M, https://eprint.iacr.org/2019/458.pdf pag.5
@@ -137,19 +143,18 @@ func PoseidonHash(inp [T]*ff.Element) (*ff.Element, error) {
 		mix(state, newState, constM)
 		state, newState = newState, state
 	}
-	return state[0], nil
+	rE := state[0]
+	r := big.NewInt(0)
+	rE.ToBigIntRegular(r)
+	return r, nil
 }
 
 // Hash performs the Poseidon hash over a ff.Element array
 // in chunks of 5 elements
-func Hash(arr []*ff.Element) (*ff.Element, error) {
-	if !utils.CheckElementArrayInField(arr) {
-		return nil, errors.New("inputs values not inside Finite Field")
-	}
-
-	r := utils.NewElement().SetOne()
+func Hash(arr []*big.Int) (*big.Int, error) {
+	r := big.NewInt(int64(1))
 	for i := 0; i < len(arr); i = i + T - 1 {
-		var toHash [T]*ff.Element
+		var toHash [T]*big.Int
 		j := 0
 		for ; j < T-1; j++ {
 			if i+j >= len(arr) {
@@ -160,14 +165,14 @@ func Hash(arr []*ff.Element) (*ff.Element, error) {
 		toHash[j] = r
 		j++
 		for ; j < T; j++ {
-			toHash[j] = Zero()
+			toHash[j] = big.NewInt(0)
 		}
 
 		ph, err := PoseidonHash(toHash)
 		if err != nil {
 			return nil, err
 		}
-		r.Add(r, ph)
+		modQ(r.Add(r, ph))
 	}
 
 	return r, nil
@@ -175,19 +180,19 @@ func Hash(arr []*ff.Element) (*ff.Element, error) {
 
 // HashBytes hashes a msg byte slice by blocks of 31 bytes encoded as
 // little-endian
-func HashBytes(b []byte) (*ff.Element, error) {
+func HashBytes(b []byte) (*big.Int, error) {
 	n := 31
-	bElems := make([]*ff.Element, 0, len(b)/n+1)
+	bElems := make([]*big.Int, 0, len(b)/n+1)
 	for i := 0; i < len(b)/n; i++ {
 		v := big.NewInt(int64(0))
 		utils.SetBigIntFromLEBytes(v, b[n*i:n*(i+1)])
-		bElems = append(bElems, utils.NewElement().SetBigInt(v))
+		bElems = append(bElems, v)
 
 	}
 	if len(b)%n != 0 {
 		v := big.NewInt(int64(0))
 		utils.SetBigIntFromLEBytes(v, b[(len(b)/n)*n:])
-		bElems = append(bElems, utils.NewElement().SetBigInt(v))
+		bElems = append(bElems, v)
 	}
 	return Hash(bElems)
 }
diff --git a/poseidon/poseidon_test.go b/poseidon/poseidon_test.go
index b6791ef..59016cd 100644
--- a/poseidon/poseidon_test.go
+++ b/poseidon/poseidon_test.go
@@ -5,7 +5,6 @@ import (
 	"math/big"
 	"testing"
 
-	"github.com/iden3/go-iden3-crypto/ff"
 	"github.com/iden3/go-iden3-crypto/utils"
 	"github.com/stretchr/testify/assert"
 	"golang.org/x/crypto/blake2b"
@@ -17,46 +16,58 @@ func TestBlake2bVersion(t *testing.T) {
 }
 
 func TestPoseidon(t *testing.T) {
-	b1 := utils.NewElement().SetUint64(1)
-	b2 := utils.NewElement().SetUint64(2)
-	h, err := Hash([]*ff.Element{b1, b2})
+	b1 := big.NewInt(1)
+	b2 := big.NewInt(2)
+	h, err := Hash([]*big.Int{b1, b2})
 	assert.Nil(t, err)
 	assert.Equal(t, "4932297968297298434239270129193057052722409868268166443802652458940273154855", h.String())
 
-	b3 := utils.NewElement().SetUint64(3)
-	b4 := utils.NewElement().SetUint64(4)
-	h, err = Hash([]*ff.Element{b3, b4})
+	b3 := big.NewInt(3)
+	b4 := big.NewInt(4)
+	h, err = Hash([]*big.Int{b3, b4})
 	assert.Nil(t, err)
 	assert.Equal(t, "4635491972858758537477743930622086396911540895966845494943021655521913507504", h.String())
 
+	b5 := big.NewInt(5)
+	b6 := big.NewInt(6)
+	b7 := big.NewInt(7)
+	b8 := big.NewInt(8)
+	b9 := big.NewInt(9)
+	b10 := big.NewInt(10)
+	b11 := big.NewInt(11)
+	b12 := big.NewInt(12)
+	h, err = Hash([]*big.Int{b1, b2, b3, b4, b5, b6, b7, b8, b9, b10, b11, b12})
+	assert.Nil(t, err)
+	assert.Equal(t, "15278801138972282646981503374384603641625274360649669926363020545395022098027", h.String())
+
 	msg := []byte("Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.")
 	n := 31
-	msgElems := make([]*ff.Element, 0, len(msg)/n+1)
+	msgElems := make([]*big.Int, 0, len(msg)/n+1)
 	for i := 0; i < len(msg)/n; i++ {
 		v := new(big.Int)
 		utils.SetBigIntFromLEBytes(v, msg[n*i:n*(i+1)])
-		msgElems = append(msgElems, utils.NewElement().SetBigInt(v))
+		msgElems = append(msgElems, v)
 	}
 	if len(msg)%n != 0 {
 		v := new(big.Int)
 		utils.SetBigIntFromLEBytes(v, msg[(len(msg)/n)*n:])
-		msgElems = append(msgElems, utils.NewElement().SetBigInt(v))
+		msgElems = append(msgElems, v)
 	}
 	hmsg, err := Hash(msgElems)
 	assert.Nil(t, err)
 	assert.Equal(t, "16019700159595764790637132363672701294192939959594423814006267756172551741065", hmsg.String())
 
 	msg2 := []byte("Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum. Lorem ipsum dolor sit amet.")
-	msg2Elems := make([]*ff.Element, 0, len(msg2)/n+1)
+	msg2Elems := make([]*big.Int, 0, len(msg2)/n+1)
 	for i := 0; i < len(msg2)/n; i++ {
 		v := new(big.Int)
 		utils.SetBigIntFromLEBytes(v, msg2[n*i:n*(i+1)])
-		msg2Elems = append(msg2Elems, utils.NewElement().SetBigInt(v))
+		msg2Elems = append(msg2Elems, v)
 	}
 	if len(msg2)%n != 0 {
 		v := new(big.Int)
 		utils.SetBigIntFromLEBytes(v, msg2[(len(msg2)/n)*n:])
-		msg2Elems = append(msg2Elems, utils.NewElement().SetBigInt(v))
+		msg2Elems = append(msg2Elems, v)
 	}
 	hmsg2, err := Hash(msg2Elems)
 	assert.Nil(t, err)
@@ -68,29 +79,29 @@ func TestPoseidon(t *testing.T) {
 }
 
 func TestPoseidonBrokenChunks(t *testing.T) {
-	h1, err := Hash([]*ff.Element{utils.NewElement().SetUint64(0), utils.NewElement().SetUint64(1), utils.NewElement().SetUint64(2), utils.NewElement().SetUint64(3), utils.NewElement().SetUint64(4),
-		utils.NewElement().SetUint64(5), utils.NewElement().SetUint64(6), utils.NewElement().SetUint64(7), utils.NewElement().SetUint64(8), utils.NewElement().SetUint64(9)})
+	h1, err := Hash([]*big.Int{big.NewInt(0), big.NewInt(1), big.NewInt(2), big.NewInt(3), big.NewInt(4),
+		big.NewInt(5), big.NewInt(6), big.NewInt(7), big.NewInt(8), big.NewInt(9)})
 	assert.Nil(t, err)
-	h2, err := Hash([]*ff.Element{utils.NewElement().SetUint64(5), utils.NewElement().SetUint64(6), utils.NewElement().SetUint64(7), utils.NewElement().SetUint64(8), utils.NewElement().SetUint64(9),
-		utils.NewElement().SetUint64(0), utils.NewElement().SetUint64(1), utils.NewElement().SetUint64(2), utils.NewElement().SetUint64(3), utils.NewElement().SetUint64(4)})
+	h2, err := Hash([]*big.Int{big.NewInt(5), big.NewInt(6), big.NewInt(7), big.NewInt(8), big.NewInt(9),
+		big.NewInt(0), big.NewInt(1), big.NewInt(2), big.NewInt(3), big.NewInt(4)})
 	assert.Nil(t, err)
 	assert.NotEqual(t, h1, h2)
 }
 
 func TestPoseidonBrokenPadding(t *testing.T) {
-	h1, err := Hash([]*ff.Element{utils.NewElement().SetUint64(1)})
+	h1, err := Hash([]*big.Int{big.NewInt(int64(1))})
 	assert.Nil(t, err)
-	h2, err := Hash([]*ff.Element{utils.NewElement().SetUint64(1), utils.NewElement().SetUint64(0)})
+	h2, err := Hash([]*big.Int{big.NewInt(int64(1)), big.NewInt(int64(0))})
 	assert.Nil(t, err)
 	assert.NotEqual(t, h1, h2)
 }
 
 func BenchmarkPoseidon(b *testing.B) {
-	b12 := utils.NewElement().SetUint64(12)
-	b45 := utils.NewElement().SetUint64(45)
-	b78 := utils.NewElement().SetUint64(78)
-	b41 := utils.NewElement().SetUint64(41)
-	bigArray4 := []*ff.Element{b12, b45, b78, b41}
+	b12 := big.NewInt(int64(12))
+	b45 := big.NewInt(int64(45))
+	b78 := big.NewInt(int64(78))
+	b41 := big.NewInt(int64(41))
+	bigArray4 := []*big.Int{b12, b45, b78, b41}
 
 	for i := 0; i < b.N; i++ {
 		Hash(bigArray4)
@@ -98,11 +109,12 @@ func BenchmarkPoseidon(b *testing.B) {
 }
 
 func BenchmarkPoseidonLarge(b *testing.B) {
-	b12 := utils.NewElement().SetString("11384336176656855268977457483345535180380036354188103142384839473266348197733")
-	b45 := utils.NewElement().SetString("11384336176656855268977457483345535180380036354188103142384839473266348197733")
-	b78 := utils.NewElement().SetString("11384336176656855268977457483345535180380036354188103142384839473266348197733")
-	b41 := utils.NewElement().SetString("11384336176656855268977457483345535180380036354188103142384839473266348197733")
-	bigArray4 := []*ff.Element{b12, b45, b78, b41}
+	b12 := utils.NewIntFromString("11384336176656855268977457483345535180380036354188103142384839473266348197733")
+	b45 := utils.NewIntFromString("11384336176656855268977457483345535180380036354188103142384839473266348197733")
+	b78 := utils.NewIntFromString("11384336176656855268977457483345535180380036354188103142384839473266348197733")
+	b41 := utils.NewIntFromString("11384336176656855268977457483345535180380036354188103142384839473266348197733")
+
+	bigArray4 := []*big.Int{b12, b45, b78, b41}
 
 	for i := 0; i < b.N; i++ {
 		Hash(bigArray4)
diff --git a/utils/utils.go b/utils/utils.go
index 188d0ff..84628cc 100644
--- a/utils/utils.go
+++ b/utils/utils.go
@@ -108,18 +108,10 @@ func CheckBigIntArrayInField(arr []*big.Int) bool {
 	return true
 }
 
-// CheckElementArrayInField checks if given *ff.Element fits in a Field Q element
-func CheckElementArrayInField(arr []*ff.Element) bool {
-	for _, aE := range arr {
-		a := big.NewInt(0)
-		aE.ToBigIntRegular(a)
-		if !CheckBigIntInField(a) {
-			return false
-		}
+func BigIntArrayToElementArray(bi []*big.Int) []*ff.Element {
+	var o []*ff.Element
+	for i := range bi {
+		o = append(o, ff.NewElement().SetBigInt(bi[i]))
 	}
-	return true
-}
-
-func NewElement() *ff.Element {
-	return &ff.Element{0, 0, 0, 0}
+	return o
 }