Patent ID: 7725099
Filing Date: 2010-05-25
Classification: H04M

Abstract:
1. A computer-readable recording medium that stores therein a computer program that causes a computer in a mobile terminal device to lock the mobile terminal device so that the mobile terminal device can not be used, the computer program causes the computer to execute: receiving e-mails via a communication network; analyzing received e-mails for an e-mail containing a set lock number and a request for a lock operation; managing authentication information; calculating a lock number from the authentication information based upon at least one of information relating to a transmission time of the e-mail, and communication history information of a previous day or earlier that is stored in the mobile terminal device; checking whether the set lock number matches with the calculated lock number; and performing a locking operation to lock the mobile terminal device when the checking indicates that the set lock number matches with the calculated lock number.