The method 1, further comprising the step of authenticating one or more of said marked items, by verifying that {HEAD ~ a decrypted unique reference} identical to {TAIL ~ a generated unique reference} can be derived by decrypting a unique code on a marked item with said unique key 
The method 1 , further comprising the step of authenticating one or more of said marked items , by verifying that { HEAD ~ a decrypted unique reference } identical to { TAIL ~ a generated unique reference } can be derived by decrypting a unique code on a marked item with said unique key
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH