diff --git a/.gitignore b/.gitignore
index 66a47c7..31f4aa4 100644
--- a/.gitignore
+++ b/.gitignore
@@ -9,3 +9,4 @@
 arm11/fastboot3DS.elf
 fastboot3DS.firm
 fastboot3DS*.7z
+fastboot3DS_priv.key
diff --git a/arm9/data/fastboot3DS_pubkey.bin b/arm9/data/fastboot3DS_pubkey.bin
new file mode 100644
index 0000000..4b705b9
--- /dev/null
+++ b/arm9/data/fastboot3DS_pubkey.bin
Binary files differ
diff --git a/include/arm9/hardware/crypto.h b/include/arm9/hardware/crypto.h
index a873e6c..51c6ce5 100644
--- a/include/arm9/hardware/crypto.h
+++ b/include/arm9/hardware/crypto.h
@@ -312,6 +312,7 @@
 
 /**
  * @brief      Verifies a RSA 2048 SHA 256 signature.
+ * @brief      Note: This function skips the ASN.1 data and is therefore not safe.
  *
  * @param[in]  encSig   Pointer to encrypted source signature.
  * @param[in]  data     Pointer to the data to hash.
diff --git a/signFirm.sh b/signFirm.sh
new file mode 100755
index 0000000..59d28cb
--- /dev/null
+++ b/signFirm.sh
@@ -0,0 +1,5 @@
+#!/bin/bash
+
+dd if=fastboot3DS.firm of=/tmp/fastboot3DS_firm_header.bin bs=256 count=1
+openssl dgst -sha256 -sign fastboot3DS_priv.key -out /tmp/fastboot3DS_firm_header.sig /tmp/fastboot3DS_firm_header.bin
+dd if=/tmp/fastboot3DS_firm_header.sig of=fastboot3DS.firm bs=256 count=1 seek=1 conv=notrunc
diff --git a/source/arm9/gui/menu_update.c b/source/arm9/gui/menu_update.c
index 405b3cc..de86ac6 100644
--- a/source/arm9/gui/menu_update.c
+++ b/source/arm9/gui/menu_update.c
@@ -34,7 +34,7 @@
 
 #define MIN_UPDATE_SIZE	0x1000
 
-static const char *updateFilePath = "sdmc:/fastboot3ds.bin";
+static const char *updateFilePath = "sdmc:/fastboot3DS.firm";
 static const char *installPath = "firm0";
 
 bool menuUpdateLoader()