diff --git a/access.lua b/access.lua
index 8ef415d..4636017 100644
--- a/access.lua
+++ b/access.lua
@@ -7,7 +7,7 @@
 --
 
 -- Get the `cache` persistent shared table
-cache = ngx.shared.cache
+local cache = ngx.shared.cache
 
 -- Generate a unique token if it has not been generated yet
 srvkey = cache:get("srvkey")
@@ -17,14 +17,10 @@ if not srvkey then
 end
 
 -- Initialize and get configuration
-config = require "config"
-conf = config.get_config()
-
--- Initialize the non-persistent cookie table
-cookies = {}
+local conf = config.get_config()
 
 -- Import helpers
-hlp = require "helpers"
+local hlp = require "helpers"
 
 -- Just a note for the client to know that he passed through the SSO
 ngx.header["X-SSO-WAT"] = "You've just been SSOed"
@@ -99,8 +95,7 @@ then
             -- current one, create a redirection with a CDA key
             if  not string.match(back_url, "^http[s]?://"..ngx.var.host.."/")
             and not string.match(back_url, ".*"..conf.login_arg.."=%d+$") then
-                cda_key = random_string()
-                cache:set(cda_key, ngx.var.cookie_SSOwAuthUser, 10)
+                local cda_key = hlp.set_cda_key()
                 if string.match(back_url, ".*?.*") then
                     back_url = back_url.."&"
                 else
diff --git a/helpers.lua b/helpers.lua
index 696af76..a663399 100644
--- a/helpers.lua
+++ b/helpers.lua
@@ -7,6 +7,11 @@
 
 module('helpers', package.seeall)
 
+local cache = ngx.shared.cache
+local conf = config.get_config()
+local cookies = {}
+
+
 -- Read a FS stored file
 function read_file(file)
     local f = io.open(file, "rb")
@@ -80,6 +85,14 @@ function uri_args_string (args)
 end
 
 
+-- Set the Cross-Domain-Authentication key for a specific user
+function set_cda_key ()
+    local cda_key = random_string()
+    cache:set(cda_key, ngx.var.cookie_SSOwAuthUser, 10)
+    return cda_key
+end
+
+
 -- Compute and set the authentication cookie
 --
 -- Sets 3 cookies containing:
diff --git a/init.lua b/init.lua
index cbbe0e5..24d0f9b 100644
--- a/init.lua
+++ b/init.lua
@@ -15,12 +15,13 @@ script_path = string.sub(debug.getinfo(1).source, 2, -9)
 package.path = package.path .. ";"..script_path.."?.lua"
 
 -- Load libraries
-json = require "json"
-lualdap = require "lualdap"
-math = require "math"
-hige = require "hige"
-lfs = require "lfs"
-socket = require "socket"
+local json = require "json"
+local lualdap = require "lualdap"
+local math = require "math"
+local hige = require "hige"
+local lfs = require "lfs"
+local socket = require "socket"
+local config = require "config"
 
 -- Persistent shared table
 flashs = {}