diff --git a/sm9/bn_pair_test.go b/sm9/bn_pair_test.go
index b3a0755..c45b707 100644
--- a/sm9/bn_pair_test.go
+++ b/sm9/bn_pair_test.go
@@ -1,7 +1,6 @@
 package sm9
 
 import (
-	"encoding/hex"
 	"math/big"
 	"testing"
 )
@@ -51,131 +50,6 @@ func init() {
 	expected_b2_2.z.y.y = *fromBigInt(bigFromHex("934FDDA6D3AB48C8571CE2354B79742AA498CB8CDDE6BD1FA5946345A1A652F6"))
 }
 
-func Test_gfpBasicOperations(t *testing.T) {
-	x := fromBigInt(bigFromHex("85AEF3D078640C98597B6027B441A01FF1DD2C190F5E93C454806C11D8806141"))
-	y := fromBigInt(bigFromHex("3722755292130B08D2AAB97FD34EC120EE265948D19C17ABF9B7213BAF82D65B"))
-	expectedAdd := fromBigInt(bigFromHex("0691692307d370af56226e57920199fbbe10f216c67fbc9468c7f225a4b1f21f"))
-	expectedSub := fromBigInt(bigFromHex("67b381821c52a5624f3304a8149be8461e3bc07adcb872c38aa65051ba53ba97"))
-	expectedNeg := fromBigInt(bigFromHex("7f1d8aad70909be90358f1d02240062433cc3a0248ded72febb879ec33ce6f22"))
-	expectedMul := fromBigInt(bigFromHex("3d08bbad376584e4f74bd31f78f716372b96ba8c3f939c12b8d54e79b6489e76"))
-	expectedMul2 := fromBigInt(bigFromHex("1df94a9e05a559ff38e0ab50cece734dc058d33738ceacaa15986a67cbff1ef6"))
-
-	ret := &gfP{}
-	gfpAdd(ret, x, y)
-	if *expectedAdd != *ret {
-		t.Errorf("add not same")
-	}
-
-	gfpSub(ret, y, x)
-	if *expectedSub != *ret {
-		t.Errorf("sub not same")
-	}
-
-	gfpNeg(ret, y)
-	if *expectedNeg != *ret {
-		t.Errorf("neg not same")
-	}
-
-	gfpMul(ret, x, y)
-	if *expectedMul != *ret {
-		t.Errorf("mul not same")
-	}
-
-	gfpMul(ret, ret, ret)
-	if *expectedMul2 != *ret {
-		t.Errorf("mul not same")
-	}
-}
-
-func TestGfpExp(t *testing.T) {
-	xI := bigFromHex("9093a2b979e6186f43a9b28d41ba644d533377f2ede8c66b19774bf4a9c7a596")
-	x := fromBigInt(xI)
-	ret, ret3 := &gfP{}, &gfP{}
-	ret.exp(x, pMinus2)
-
-	gfpMul(ret3, x, ret)
-	if *ret3 != *one {
-		t.Errorf("got %v, expected %v\n", ret3, one)
-	}
-	montDecode(ret, ret)
-
-	ret2 := new(big.Int).Exp(xI, bigFromHex("b640000002a3a6f1d603ab4ff58ec74521f2934b1a7aeedbe56f9b27e351457b"), p)
-	if hex.EncodeToString(ret2.Bytes()) != ret.String() {
-		t.Errorf("exp not same, got %v, expected %v\n", ret, hex.EncodeToString(ret2.Bytes()))
-	}
-
-	ret1 := &gfP{}
-	ret1.exp2(x, bigFromHex("b640000002a3a6f1d603ab4ff58ec74521f2934b1a7aeedbe56f9b27e351457b"))
-	montDecode(ret1, ret1)
-	if hex.EncodeToString(ret2.Bytes()) != ret1.String() {
-		t.Errorf("exp not same, got %v, expected %v\n", ret1, hex.EncodeToString(ret2.Bytes()))
-	}
-
-	xInv := new(big.Int).ModInverse(xI, p)
-	if hex.EncodeToString(ret2.Bytes()) != hex.EncodeToString(xInv.Bytes()) {
-		t.Errorf("exp not same, got %v, expected %v\n", hex.EncodeToString(ret2.Bytes()), hex.EncodeToString(xInv.Bytes()))
-	}
-
-	x2 := new(big.Int).Mul(xI, xInv)
-	x2.Mod(x2, p)
-	if big.NewInt(1).Cmp(x2) != 0 {
-		t.Errorf("not same")
-	}
-
-	xInvGfp := fromBigInt(xInv)
-	gfpMul(ret, x, xInvGfp)
-	if *ret != *one {
-		t.Errorf("got %v, expected %v", ret, one)
-	}
-}
-
-func TestGfpInvert(t *testing.T) {
-	x := fromBigInt(bigFromHex("85AEF3D078640C98597B6027B441A01FF1DD2C190F5E93C454806C11D8806141"))
-	xInv := &gfP{}
-	xInv.Invert(x)
-	y := &gfP{}
-	gfpMul(y, x, xInv)
-	if *y != *one {
-		t.Errorf("got %v, expected %v", y, one)
-	}
-}
-
-func TestGfpDiv(t *testing.T) {
-	x := fromBigInt(bigFromHex("9093a2b979e6186f43a9b28d41ba644d533377f2ede8c66b19774bf4a9c7a596"))
-	ret := &gfP{}
-	ret.Div2(x)
-	gfpAdd(ret, ret, ret)
-	if *ret != *x {
-		t.Errorf("got %v, expected %v", ret, x)
-	}
-}
-
-func TestGfpSqrt(t *testing.T) {
-	tests := []string{
-		"9093a2b979e6186f43a9b28d41ba644d533377f2ede8c66b19774bf4a9c7a596",
-		"92fe90b700fbd4d8cc177d300ed16e4e15471a681b2c9e3728c1b82c885e49c2",
-	}
-	for i, test := range tests {
-		y2 := bigFromHex(test)
-		y21 := new(big.Int).ModSqrt(y2, p)
-
-		y3 := new(big.Int).Mul(y21, y21)
-		y3.Mod(y3, p)
-		if y2.Cmp(y3) != 0 {
-			t.Error("Invalid sqrt")
-		}
-
-		tmp := fromBigInt(y2)
-		tmp.Sqrt(tmp)
-		montDecode(tmp, tmp)
-		var res [32]byte
-		tmp.Marshal(res[:])
-		if hex.EncodeToString(res[:]) != hex.EncodeToString(y21.Bytes()) {
-			t.Errorf("case %v, got %v, expected %v\n", i, hex.EncodeToString(res[:]), hex.EncodeToString(y21.Bytes()))
-		}
-	}
-}
-
 func Test_Pairing_A2(t *testing.T) {
 	pk := bigFromHex("0130E78459D78545CB54C587E02CF480CE0B66340F319F348A1D5B1F2DC5F4")
 	g2 := &G2{}
diff --git a/sm9/gfp.go b/sm9/gfp.go
index 3698c7d..a9370ca 100644
--- a/sm9/gfp.go
+++ b/sm9/gfp.go
@@ -103,24 +103,6 @@ func (e *gfP) exp(f *gfP, bits [4]uint64) {
 	e.Set(sum)
 }
 
-func (e *gfP) exp2(f *gfP, power *big.Int) *gfP {
-	sum := &gfP{}
-	sum.Set(one)
-	t := &gfP{}
-
-	for i := power.BitLen() - 1; i >= 0; i-- {
-		gfpMul(t, sum, sum)
-		if power.Bit(i) != 0 {
-			gfpMul(sum, t, f)
-		} else {
-			sum.Set(t)
-		}
-	}
-
-	e.Set(sum)
-	return e
-}
-
 func (e *gfP) Invert(f *gfP) {
 	e.exp(f, pMinus2)
 }
diff --git a/sm9/gfp_test.go b/sm9/gfp_test.go
index ef5583e..a3b096f 100644
--- a/sm9/gfp_test.go
+++ b/sm9/gfp_test.go
@@ -6,6 +6,77 @@ import (
 	"testing"
 )
 
+func Test_gfpBasicOperations(t *testing.T) {
+	x := fromBigInt(bigFromHex("85AEF3D078640C98597B6027B441A01FF1DD2C190F5E93C454806C11D8806141"))
+	y := fromBigInt(bigFromHex("3722755292130B08D2AAB97FD34EC120EE265948D19C17ABF9B7213BAF82D65B"))
+	expectedAdd := fromBigInt(bigFromHex("0691692307d370af56226e57920199fbbe10f216c67fbc9468c7f225a4b1f21f"))
+	expectedSub := fromBigInt(bigFromHex("67b381821c52a5624f3304a8149be8461e3bc07adcb872c38aa65051ba53ba97"))
+	expectedNeg := fromBigInt(bigFromHex("7f1d8aad70909be90358f1d02240062433cc3a0248ded72febb879ec33ce6f22"))
+	expectedMul := fromBigInt(bigFromHex("3d08bbad376584e4f74bd31f78f716372b96ba8c3f939c12b8d54e79b6489e76"))
+	expectedMul2 := fromBigInt(bigFromHex("1df94a9e05a559ff38e0ab50cece734dc058d33738ceacaa15986a67cbff1ef6"))
+
+	ret := &gfP{}
+	gfpAdd(ret, x, y)
+	if *expectedAdd != *ret {
+		t.Errorf("add not same")
+	}
+
+	gfpSub(ret, y, x)
+	if *expectedSub != *ret {
+		t.Errorf("sub not same")
+	}
+
+	gfpNeg(ret, y)
+	if *expectedNeg != *ret {
+		t.Errorf("neg not same")
+	}
+
+	gfpMul(ret, x, y)
+	if *expectedMul != *ret {
+		t.Errorf("mul not same")
+	}
+
+	gfpMul(ret, ret, ret)
+	if *expectedMul2 != *ret {
+		t.Errorf("mul not same")
+	}
+}
+
+func TestGfpExp(t *testing.T) {
+	xI := bigFromHex("9093a2b979e6186f43a9b28d41ba644d533377f2ede8c66b19774bf4a9c7a596")
+	x := fromBigInt(xI)
+	ret, ret3 := &gfP{}, &gfP{}
+	ret.exp(x, pMinus2)
+
+	gfpMul(ret3, x, ret)
+	if *ret3 != *one {
+		t.Errorf("got %v, expected %v\n", ret3, one)
+	}
+	montDecode(ret, ret)
+
+	ret2 := new(big.Int).Exp(xI, bigFromHex("b640000002a3a6f1d603ab4ff58ec74521f2934b1a7aeedbe56f9b27e351457b"), p)
+	if hex.EncodeToString(ret2.Bytes()) != ret.String() {
+		t.Errorf("exp not same, got %v, expected %v\n", ret, hex.EncodeToString(ret2.Bytes()))
+	}
+
+	xInv := new(big.Int).ModInverse(xI, p)
+	if hex.EncodeToString(ret2.Bytes()) != hex.EncodeToString(xInv.Bytes()) {
+		t.Errorf("exp not same, got %v, expected %v\n", hex.EncodeToString(ret2.Bytes()), hex.EncodeToString(xInv.Bytes()))
+	}
+
+	x2 := new(big.Int).Mul(xI, xInv)
+	x2.Mod(x2, p)
+	if big.NewInt(1).Cmp(x2) != 0 {
+		t.Errorf("not same")
+	}
+
+	xInvGfp := fromBigInt(xInv)
+	gfpMul(ret, x, xInvGfp)
+	if *ret != *one {
+		t.Errorf("got %v, expected %v", ret, one)
+	}
+}
+
 func TestSqrt(t *testing.T) {
 	tests := []string{
 		"9093a2b979e6186f43a9b28d41ba644d533377f2ede8c66b19774bf4a9c7a596",