diff --git a/kyber_1024/kyber_1024_test.go b/kyber_1024/kyber_1024_test.go
index 3f40b98..8c7c8fb 100644
--- a/kyber_1024/kyber_1024_test.go
+++ b/kyber_1024/kyber_1024_test.go
@@ -16,6 +16,7 @@ import(
 
 func Test_kyber1024(t *testing.T){
 	var curpos,temp_len uint
+	kyber_ops.Set_test_rand()
 	data,err:=os.ReadFile("kyber1024-kat.rsp")
 	if err!=nil{
 		t.Fatal(err)
@@ -54,6 +55,7 @@ func Test_kyber1024(t *testing.T){
 
 func Test_kyber1024_90s(t *testing.T){
 	var curpos,temp_len uint
+	kyber_ops.Set_test_rand()
 	data,err:=os.ReadFile("kyber1024_90s-kat.rsp")
 	if err!=nil{
 		t.Fatal(err)
diff --git a/kyber_512/kyber_512_test.go b/kyber_512/kyber_512_test.go
index 20b2902..fa2de96 100644
--- a/kyber_512/kyber_512_test.go
+++ b/kyber_512/kyber_512_test.go
@@ -16,6 +16,7 @@ import(
 
 func Test_kyber512(t *testing.T){
 	var curpos,temp_len uint
+	kyber_ops.Set_test_rand()
 	data,err:=os.ReadFile("kyber512-kat.rsp")
 	if err!=nil{
 		t.Fatal(err)
@@ -54,6 +55,7 @@ func Test_kyber512(t *testing.T){
 
 func Test_kyber512_90s(t *testing.T){
 	var curpos,temp_len uint
+	kyber_ops.Set_test_rand()
 	data,err:=os.ReadFile("kyber512_90s-kat.rsp")
 	if err!=nil{
 		t.Fatal(err)
diff --git a/kyber_768/kyber_768_test.go b/kyber_768/kyber_768_test.go
index d53bfd8..cefd9a0 100644
--- a/kyber_768/kyber_768_test.go
+++ b/kyber_768/kyber_768_test.go
@@ -16,6 +16,7 @@ import(
 
 func Test_kyber_768(t *testing.T){
 	var curpos,temp_len uint
+	kyber_ops.Set_test_rand()
 	data,err:=os.ReadFile("kyber768-kat.rsp")
 	if err!=nil{
 		t.Fatal(err)
@@ -54,6 +55,7 @@ func Test_kyber_768(t *testing.T){
 
 func Test_kyber_768_90s(t *testing.T){
 	var curpos,temp_len uint
+	kyber_ops.Set_test_rand()
 	data,err:=os.ReadFile("kyber768_90s-kat.rsp")
 	if err!=nil{
 		t.Fatal(err)
diff --git a/kyber_ops/Common.go b/kyber_ops/Common.go
index 606f2a0..e19fc4c 100644
--- a/kyber_ops/Common.go
+++ b/kyber_ops/Common.go
@@ -42,6 +42,11 @@ func Init_Seed(str string)(err error){
 }
 
 var rng rng_info
+var test_rand bool=false
+
+func Set_test_rand(){
+	test_rand=true
+}
 
 func init_rng(seed *[48]byte){
 	rng.iv=[16]byte{}
@@ -50,6 +55,10 @@ func init_rng(seed *[48]byte){
 }
 
 func Read_RNG(rand_data []byte){
+	if !test_rand{
+		rand.Read(rand_data)
+		return
+	}
 	cipher,_:=aes.NewCipher(rng.key[:])
 	length:=len(rand_data)
 	for cur:=0;cur<length;cur+=16{
@@ -79,12 +88,6 @@ func update_rng(addion *[48]byte){
 	}
 }
 
-func init(){
-	var bytes48 [48]byte
-	rand.Read(bytes48[:])
-	init_rng(&bytes48)
-}
-
 func CBD2(B *[128]byte,f *[256]int16){
 	const b101=0x55555555
 	var(
@@ -318,7 +321,7 @@ func CSUBQ_vec[v vec](f v){
 }
 
 func aes_count(iv *[16]byte){
-	for i:=15;i>0;i--{
+	for i:=15;i>=0;i--{
 		iv[i]++
 		if iv[i]>0{
 			break