Controlling access to stored information.

摘要

Access to stored information by a user is controlled by comparing an actual geographic position and/or an actual date/time with a geographic region and/or a date/time interval within which access to the stored information is authorized. The actual geographic position where the stored information is located, and the actual date/time can be determined, for example, based on signals received at a receiver supplying reliable position and time information, such as a GPS receiver. Access to the stored information is authorized if the actual geographic position and/or date/time falls within the authorized geographic region and/or date/time interval. The position and date/time information supplied by the receiver may be cryptographically signed and encrypted.