Pipes password from kdialog to geli attach

[yarodin]

init:
password=`kdialog --password "Enter the password"`
echo $password|sha256|geli init -s 4096 -P -K - /dev/ad0s1e

atach:
password=`kdialog --password "Enter the password"`
echo $password|sha256|geli attach -p -k - /dev/ad0s1e

Is it very unsecure? May be a better method exists?