Patent ID: 7891009
Filing Date: 2011-02-15
Classification: G06F

Abstract:
1. A time data checking device, comprising: a time data provision unit that provides a first time indication which can be changed by a user; a first memory that stores the first time indication; a time indication change determining unit that determines a change in the first time indication performed externally to the time data checking device, such that a changed first time indication is generated by changing the first time indication to become the changed first time indication; a time indication difference determining unit that determines the difference between the stored first time indication and the changed first time indication; a second memory that stores the difference between the stored first time indication and the changed first time indication or the changed first time indication or both; a third memory that stores a trustworthy second time indication; and a checking unit that checks whether a predetermined criterion is met by using the first time indication, the difference between the stored first time indication and the changed first time indication, and the trustworthy second time indication, wherein the stored first time indication cannot be changed by a user, or wherein the stored difference between the stored first time indication and the changed first time indication or the changed first time indication or both cannot be changed by a user.