diff --git a/installer/portable/update-filebot.sh b/installer/portable/update-filebot.sh
index 3b1fac89..ecc4d822 100755
--- a/installer/portable/update-filebot.sh
+++ b/installer/portable/update-filebot.sh
@@ -1,4 +1,4 @@
-#!/bin/sh
+#!/bin/sh -xu
 PRG="$0"
 
 # resolve relative symlinks
@@ -18,18 +18,23 @@ FILEBOT_HOME=`cd "$PRG_DIR" && pwd`
 
 
 # update core application files
-PACKAGE_NAME="CHANGES.tar.xz.gpg"
+PACKAGE_NAME="DELTA.tar.xz"
 PACKAGE_FILE="$FILEBOT_HOME/$PACKAGE_NAME"
-PACKAGE_URL="https://get.filebot.net/filebot/latest/$PACKAGE_NAME"
+PACKAGE_URL="@{link.release.index}/HEAD/$PACKAGE_NAME"
+SIGNATURE_FILE="$PACKAGE_FILE.asc"
+SIGNATURE_URL="$PACKAGE_URL.asc"
 
+# use *.asc file to check for updates
 echo "Update $PACKAGE_FILE"
-HTTP_CODE=`curl -L -o "$PACKAGE_FILE" -z "$PACKAGE_FILE" --retry 5 "$PACKAGE_URL" -w "%{http_code}"`
+HTTP_CODE=`curl -L -o "$SIGNATURE_FILE" -z "$SIGNATURE_FILE" --retry 5 "$SIGNATURE_URL" -w "%{http_code}"`
 
 if [ $HTTP_CODE -ne 200 ]; then
 	echo "$HTTP_CODE NO UPDATE"
 	exit 1
 fi
 
+curl -L -o "$PACKAGE_FILE" --retry 5 "$PACKAGE_URL"
+
 
 # initialize gpg
 GPG_HOME="$FILEBOT_HOME/data/.gpg"
@@ -38,5 +43,7 @@ if [ ! -d "$GPG_HOME" ]; then
 	mkdir -p "$GPG_HOME" && chmod 700 "$GPG_HOME" && gpg --homedir "$GPG_HOME" --import "$FILEBOT_HOME/maintainer.pub"
 fi
 
-# verify signature and extract jar
-gpg --batch --yes --homedir "$GPG_HOME" --trusted-key "4E402EBF7C3C6A71" --decrypt "$PACKAGE_FILE" | tar -xJvf "-"
+# verify signature and extract tar
+if gpg --batch --yes --homedir "$GPG_HOME" --trusted-key "B0976E51E5C047AD0FD051294E402EBF7C3C6A71" --verify "$SIGNATURE_FILE" "$PACKAGE_FILE"; then
+	tar -xJvf "$PACKAGE_FILE" && rm -v "$PACKAGE_FILE"
+fi