diff --git a/script/config.sh b/script/config.sh
index 70e20ee..6f32dfe 100644
--- a/script/config.sh
+++ b/script/config.sh
@@ -32,6 +32,11 @@ export LVSWAPNAME="swap"
 # 1 : Overwrite the existing logical volume as root vlume. 0 : Create new logical volume as root volume. 
 export OVERWRITEINSTALL=0
 
+# Do not touch this parameter, unless you understand precisely what you are doing.
+# This is a paameter value of the --iter-time option for cyrptsetup command. 
+# If you specify 1000, that means 1000mSec. 0 means compile default.  
+export ITERTIME=0
+
 # Void Linux only. Ignored in Ubuntu.
 # The font size of the void-installer
 export XTERMFONTSIZE=11
diff --git a/script/lib/common.sh b/script/lib/common.sh
index 11c3fbd..43a9bb2 100644
--- a/script/lib/common.sh
+++ b/script/lib/common.sh
@@ -169,7 +169,7 @@ function pre_install() {
 
 		# Encrypt the partition to install Linux
 		echo "...Initializing \"${DEV}${CRYPTPARTITION}\" as crypt partition"
-		printf %s "${PASSPHRASE}" | cryptsetup luksFormat --type=luks1 --key-file - --batch-mode "${DEV}${CRYPTPARTITION}"
+		printf %s "${PASSPHRASE}" | cryptsetup luksFormat --iter-time "${ITERTIME}" --type=luks1 --key-file - --batch-mode "${DEV}${CRYPTPARTITION}"
 
 	fi	# if erase all