Importance

Loading Importance Indicators...

Abstract

In order that a transmitting person of an electronic mail specifies an open date and hour of the electronic mail, the electronic mail is transmitted after the open date and hour is added to it. If a current date and hour is located on and after the open date and hour, the open of the electronic mail is prevented. Such prevention is attained by encrypting the electronic mail and decoding it if the current date and hour is located before the open date and hour. Moreover, when the current date and hour is changed to another current date and hour, the open date and hour is changed on the basis of the current date and hour and the other current date and hour. In this case, a relative time between the current date and hour prior to the change and the open date and hour prior to the change is equal to a relative time between the current date and hour after the change and the open date and hour after the change. This change of the open date and hour disables a receiving person from opening the electronic mail by changing the current date and hour.

Loading the Abstract Image...

First Claim