Embodiments of the invention enable cardholders conducting {HEAD ~ an online transaction} to be authenticated in real time using {TAIL ~ a challenge response application} 
to be authenticated using
Embodiments of the invention enable cardholders conducting { HEAD ~ an online transaction } to be authenticated in real time using { TAIL ~ a challenge response application }
OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL REL OTH OTH OTH REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL