a system and method for secure peer - to - peer mobile communications using cryptographic mobile unlock tokens in conjunction with mobile devices . each ck token integrates an entire cryptosystem . executing these cryptographic based functions entirely in the token have significant operational advantages over the typically memory - only tokens . a more secure , scalable , and lower overall system cost are just a few advantages of the ck token over executing these functions within the smartphone . of the many uses discussed for the ck token , mobile phone enabling , stored value and medical applications , most have centered on the use of the card in conjunction with a smartphone as the touch point in the transaction .