diff --git a/src/NoteHub/api.clj b/src/NoteHub/api.clj
index 159e6ca..f9be74c 100644
--- a/src/NoteHub/api.clj
+++ b/src/NoteHub/api.clj
@@ -1,10 +1,24 @@
-(ns NoteHub.api)
+(ns NoteHub.api
+  (:require [NoteHub.storage :as persistance]))
 
 (def api-version "1.0")
 
-(defn get-signature [& args])
+(defn- create-response
+  ([success] { :success success })
+  ([success message]
+   (assoc (create-response success) :message message)))
+
+(let [md5Instance (java.security.MessageDigest/getInstance "MD5")]
+  (defn get-signature
+    "Returns the MD5 hash for the concatenation of all passed parameters"
+    [& args]
+    (let [input (apply str args)]
+      (do (.reset md5Instance)
+          (.update md5Instance (.getBytes input))
+          (.toString (new java.math.BigInteger 1 (.digest md5Instance)) 16)))))
+
+(defn get-note [noteID])
 (defn post-note [& args])
-(defn get-note [& args])
 (defn update-note [& args])
 (defn register-publisher [& args])
 (defn revoke-publisher [& args])