diff --git a/makerom/aes_keygen.c b/makerom/aes_keygen.c
index e5a35d6..ffaa4d9 100644
--- a/makerom/aes_keygen.c
+++ b/makerom/aes_keygen.c
@@ -106,6 +106,7 @@ void n128_xor(const uint8_t *a, const uint8_t *b, uint8_t *out)
 }
 
 // keygen algorithm
+/*
 void n_aes_keygen(const uint8_t *x, uint8_t x_shift, const uint8_t *y, uint8_t y_shift, const uint8_t *keygen_constant, uint8_t *key)
 {
 	// overall algo:
@@ -121,4 +122,25 @@ void n_aes_keygen(const uint8_t *x, uint8_t x_shift, const uint8_t *y, uint8_t y
 
 	// Add secret
 	n128_add(key_xy, keygen_constant, key);
+}
+*/
+
+void ctr_aes_keygen(const uint8_t *x, const uint8_t *y, uint8_t *key)
+{
+	static const uint8_t KEYGEN_CONST[16] = { 0x1F, 0xF9, 0xE9, 0xAA, 0xC5, 0xFE, 0x04, 0x08, 0x02, 0x45, 0x91, 0xDC, 0x5D, 0x52, 0x76, 0x8A };
+
+	// overall algo:
+	// key = (((x <<< 2) ^ y) + KEYGEN_CONST) >>> 41
+	uint8_t x_rot[16], key_xy[16], key_xyc[16];
+
+	// x_rot = x <<< 2
+	n128_lrot(x, 2, x_rot);
+
+	// key_xy = x_rot ^ y
+	n128_xor(x_rot, y, key_xy);
+
+	// key_xyc = key_xy + KEYGEN_CONST
+	n128_add(key_xy, KEYGEN_CONST, key);
+
+	n128_rrot(key_xyc, 41, key);
 }
\ No newline at end of file
diff --git a/makerom/aes_keygen.h b/makerom/aes_keygen.h
index 0314744..dae87a3 100644
--- a/makerom/aes_keygen.h
+++ b/makerom/aes_keygen.h
@@ -2,11 +2,7 @@
 #include <stdint.h>
 
 /*
-	AES Key generator for the Nintendo (Handheld) Consoles
-
-	BYO keygen constants, and input >>> parameters
-
-	key = ((x >>> x_shift) ^ (y >>> y_shift)) + keygen_constant
+	AES Key generator for the Nintendo 3DS (CTR) Consoles
 */
 
-void n_aes_keygen(const uint8_t *x, uint8_t x_shift, const uint8_t *y, uint8_t y_shift, const uint8_t *keygen_constant, uint8_t *key);
+void ctr_aes_keygen(const uint8_t *x, const uint8_t *y, uint8_t *key);
diff --git a/makerom/keyset.c b/makerom/keyset.c
index d468471..3710d92 100644
--- a/makerom/keyset.c
+++ b/makerom/keyset.c
@@ -48,15 +48,6 @@ void PrintBadKeySize(char *path, u32 size)
 	fprintf(stderr,"[KEYSET ERROR] %s has invalid size (0x%x)\n",path,size);
 }
 
-u8* AesKeyScrambler(u8 *key, const u8 *keyX, const u8 *keyY)
-{
-	static const uint8_t CTR_KEYGEN_CONST[16] = { 0xEE, 0x2E, 0xA9, 0x3B, 0x45, 0x0F, 0xFC, 0xF4, 0xD5, 0x62, 0xFF, 0x02, 0x04, 0x01, 0x22, 0xC8 };
-	static const uint8_t CTR_KEYX_SHIFT = 39;
-	static const uint8_t CTR_KEYY_SHIFT = 41;
-	n_aes_keygen(keyX, CTR_KEYX_SHIFT, keyY, CTR_KEYY_SHIFT, CTR_KEYGEN_CONST, key);
-	return key;
-}
-
 int SetKeys(keys_struct *keys)
 {	
 	int result = 0;
@@ -135,7 +126,7 @@ int LoadKeysFromResources(keys_struct *keys)
 		// CIA
 		//for(int i = 0; i < 6; i++){
 		//	keys->aes.commonKey[i] = malloc(16);
-		//	AesKeyScrambler(keys->aes.commonKey[i], ctr_common_etd_keyX_ppki, ctr_common_etd_keyY_ppki[i]);
+		//	ctr_aes_keygen(ctr_common_etd_keyX_ppki, ctr_common_etd_keyY_ppki[i], keys->aes.commonKey[i]);
 		//}
 		if(keys->aes.currentCommonKey > 0xff)
 			SetCurrentCommonKey(keys,0);
diff --git a/makerom/keyset.h b/makerom/keyset.h
index 1e1db78..4ab18ff 100644
--- a/makerom/keyset.h
+++ b/makerom/keyset.h
@@ -96,6 +96,4 @@ void FreeKeys(keys_struct *keys);
 int SetCommonKey(keys_struct *keys, const u8 *key, u8 Index);
 int SetCurrentCommonKey(keys_struct *keys, u8 Index);
 int SetNormalKey(keys_struct *keys, const u8 *key);
-int SetSystemFixedKey(keys_struct *keys, const u8 *key);
-
-u8* AesKeyScrambler(u8 *key, const u8 *keyX, const u8 *keyY);
+int SetSystemFixedKey(keys_struct *keys, const u8 *key);
\ No newline at end of file
diff --git a/makerom/ncch.c b/makerom/ncch.c
index 577843b..e8d6412 100644
--- a/makerom/ncch.c
+++ b/makerom/ncch.c
@@ -1,4 +1,5 @@
 #include "lib.h"
+#include "aes_keygen.h"
 #include "ncch_build.h"
 #include "exheader_build.h"
 #include "exheader_read.h"
@@ -1043,12 +1044,12 @@ bool SetNcchKeys(keys_struct *keys, ncch_hdr *hdr)
 	}
 	
 	if(keys->aes.ncchKeyX[0])
-		AesKeyScrambler(keys->aes.ncchKey0,keys->aes.ncchKeyX[0],hdr->signature);
+		ctr_aes_keygen(keys->aes.ncchKeyX[0],hdr->signature,keys->aes.ncchKey0);
 	else
 		return false;
 	
 	if(keys->aes.ncchKeyX[hdr->flags[ncchflag_CONTENT_KEYX]])
-		AesKeyScrambler(keys->aes.ncchKey1,keys->aes.ncchKeyX[hdr->flags[ncchflag_CONTENT_KEYX]],hdr->signature);
+		ctr_aes_keygen(keys->aes.ncchKeyX[ncchflag_CONTENT_KEYX], hdr->signature, keys->aes.ncchKey0);
 	else
 		return false;