Yuichi Komano Kazuo Ohta Hideyuki Miyake Atsushi Shimbo Algorithmic Tamper Proof (ATP) Counter Units for Authentication Devices Using PIN. 306-323 2009 ACNS http://dx.doi.org/10.1007/978-3-642-01957-9_19 conf/acns/2009 db/conf/acns/acns2009.html#KomanoOMS09