diff --git a/basis/backend_storage.lua b/basis/backend_storage.lua
index adc7dcd..280fefb 100644
--- a/basis/backend_storage.lua
+++ b/basis/backend_storage.lua
@@ -62,19 +62,19 @@ function backend.get_nodepos(number)
 end	
 	
 function backend.set_nodepos(number, pos)
-	storage:get_string(number, minetest.pos_to_string(pos))
+	storage:set_string(number, minetest.pos_to_string(pos))
 end	
 	
 function backend.add_nodepos(pos)
 	local num = tostring(NextNumber)
 	NextNumber = NextNumber + 1
 	storage:set_int("NextNumber", NextNumber)
-	storage:get_string(num, minetest.pos_to_string(pos))
+	storage:set_string(num, minetest.pos_to_string(pos))
 	return num
 end	
 	
 function backend.del_nodepos(number)
-	storage:get_string(number, "")
+	storage:set_string(number, "")
 end	
 
 -- delete invalid entries
@@ -87,6 +87,8 @@ function backend.delete_invalid_entries(node_def)
 			local name = techage.get_node_lvm(pos).name
 			if not node_def[name] then
 				backend.del_nodepos(number)
+			else
+				minetest.get_meta(pos):set_string("node_number", number) 
 			end
 		end
 	end
diff --git a/basis/command.lua b/basis/command.lua
index 90d3099..9f116e8 100644
--- a/basis/command.lua
+++ b/basis/command.lua
@@ -19,7 +19,7 @@ local S = function(pos) if pos then return minetest.pos_to_string(pos) end end
 
 local NodeInfoCache = {}
 local MP = minetest.get_modpath("techage")
-local use_database = minetest.settings:get_bool('techage.use_database', false)
+local use_database = minetest.settings:get_bool('techage_use_database', false)
 
 -- Localize functions to avoid table lookups (better performance)
 local string_split = string.split
@@ -60,7 +60,7 @@ end
 -- Keep the cache size small by deleting entries randomly 
 local function keep_small(number)
 	number = delete_nodeinfo_entry(number)
-	minetest.after(2, keep_small, number)
+	minetest.after(10, keep_small, number)
 end
 
 keep_small()
diff --git a/basis/storage.lua b/basis/storage.lua
index 3e4871e..d0353b7 100644
--- a/basis/storage.lua
+++ b/basis/storage.lua
@@ -26,6 +26,34 @@ local StoredNodes = 0
 local NextNum = 0
 local Timeslot = 0
 local FNAME = minetest.get_worldpath()..DIR_DELIM.."techage_metadata.txt"
+local use_marshal = minetest.settings:get_bool('techage_use_marshal', false)
+local MAR_MAGIC = 0x8e
+
+-- default functions
+local serialize = minetest.serialize
+local deserialize = minetest.deserialize
+
+if use_marshal then
+	if not techage.IE then
+		error("Please add 'secure.trusted_mods = techage' to minetest.conf!")
+	end
+	local marshal = techage.IE.require("marshal")
+	if not marshal then
+		error("Please install marshal via 'luarocks install lua-marshal'")
+	end
+	
+	serialize = marshal.encode
+
+	deserialize = function(s)
+		if s ~= "" then
+			if s:byte(1) == MAR_MAGIC then
+				return marshal.decode(s)
+			else
+				return minetest.deserialize(s)
+			end
+		end
+	end
+end
 
 local function read_file()
     local f = io.open(FNAME, "r")
@@ -51,10 +79,13 @@ minetest.register_on_shutdown(function()
 end)
 
 
+
+
+
 local function set_metadata(hash, tbl)
 	local pos = minetest.get_position_from_hash(hash)
 	tbl.USED = nil
-	local data = minetest.serialize(tbl)
+	local data = serialize(tbl)
 	local meta = minetest.get_meta(pos)
 	meta:set_string("ta_data", data)
 	meta:mark_as_private("ta_data")
@@ -65,7 +96,7 @@ local function get_metadata(hash)
 	local meta = minetest.get_meta(pos)
 	local s = meta:get_string("ta_data")
 	if s ~= "" then
-		return minetest.deserialize(s)
+		return deserialize(s)
 	end
 end
 
diff --git a/init.lua b/init.lua
index b3c167c..9d50739 100644
--- a/init.lua
+++ b/init.lua
@@ -46,6 +46,9 @@ techage.basalt_stone_enabled = minetest.settings:get_bool("techage_basalt_stone_
 techage.ore_rarity = tonumber(minetest.settings:get("techage_ore_rarity")) or 1
 techage.modified_recipes_enabled = minetest.settings:get_bool("techage_modified_recipes_enabled") ~= false
 
+-- allow to load marshal and sqlite3
+techage.IE = minetest.request_insecure_environment()
+
 -- Load support for I18n.
 techage.S = minetest.get_translator("techage")
 
@@ -296,3 +299,7 @@ end
 -- Carts
 dofile(MP.."/carts/tank_cart.lua")
 dofile(MP.."/carts/chest_cart.lua")
+
+
+-- Prevent other mods from using IE
+techage.IE = nil