초록 ▼

A method for monitoring time so that the use of protected content can be controlled includes receiving a trusted time value from a trusted authority external to a client device. When the client is no longer in communication with the trusted authority, the previously-received trusted time value is up

A method for monitoring time so that the use of protected content can be controlled includes receiving a trusted time value from a trusted authority external to a client device. When the client is no longer in communication with the trusted authority, the previously-received trusted time value is updated by use of the client's operating system counter so that a calculated trusted time value is derived for content license evaluation purposes.

대표청구항 ▼

1. A method of monitoring time, comprising: calculating, using a central processing unit (CPU), a first calculated time value corresponding to a point in time when content is used by a client on a first occasion, wherein the first calculated time value is a function of a first trusted time value rec

1. A method of monitoring time, comprising: calculating, using a central processing unit (CPU), a first calculated time value corresponding to a point in time when content is used by a client on a first occasion, wherein the first calculated time value is a function of a first trusted time value received by the client from a trusted authority external to the client during a first communication session;calculating a first time offset value corresponding to a difference between a second trusted time value and a second calculated time value, wherein the second trusted time value is received by the client from the trusted authority during a second communication session, andwherein the second calculated time value corresponds to a point in time when the second trusted time value is received by the client, and wherein the second calculated time value is a function of the first trusted time value; andcalculating an elapsed time value corresponding to a difference between a third calculated time value and a revised first calculated time value, wherein the third calculated time value corresponds to a point in time when the client attempts use of the content for a second occasion, and wherein the third calculated time value is a function of the second trusted time value, andwherein the revised first calculated time value corresponds to a combination of the first calculated time value and the first time offset value. 2. The method of claim 1 further comprising evaluating a license having temporal rules according to the elapsed time value. 3. The method of claim 1 further comprising: securely storing the first trusted time value;securely storing the first calculated time value;securely storing the second trusted time value; andsecurely storing the first time offset value. 4. The method of claim 1 wherein calculating the elapsed time value includes calculating the elapsed time value if a flag is set, the flag being indicative of the existence in the client of the first time offset value. 5. The method of claim 1 wherein calculating the first calculated time value includes combining a second time offset value with the first trusted time value, wherein the second time offset value is a function of a difference between a second counter value and a first counter value, the first counter value corresponding to a point in time when the first trusted time value is received from the trusted authority, and the second counter value corresponding to a point in time when the first calculated time value is being calculated. 6. The method of claim 5 wherein the second calculated time value is further a function of the combination of a third time offset value with the first trusted time value, wherein the third time offset value is a function of a difference between a third counter value and the first counter value, the third counter value corresponding to a point in time when the second trusted time value is received from the trusted authority. 7. The method of claim 6 wherein the third calculated time value is further a function of the combination of a fourth time offset value with the second trusted time value, wherein the fourth time offset value is a function of a difference between a fourth counter value and the third counter value, the fourth counter value corresponding to the point in time when the client attempts use of the content for the second occasion. 8. The method of claim 7 further comprising evaluating a license having temporal rules according to the elapsed time value. 9. The method of claim 7 further comprising: securely storing the first trusted time value;securely storing the first calculated time value;securely storing the second trusted time value; andsecurely storing the first time offset value. 10. The method of claim 7 wherein calculating the elapsed time value includes calculating the elapsed time value if a flag is set, the flag being indicative of the existence in the client of the first time offset value. 11. An article of manufacture for controlling the use of content and for use by a device having a processing unit, the device being adapted for communication with a trusted authority external to the device, the article of manufacture comprising: at least one non-transitory, tangible computer usable media including at least one computer program embedded therein, the at least one computer program being adapted to cause the device to perform: calculating a first calculated time value corresponding to a point in time when the content is used by the device on a first occasion, wherein the first calculated time value is a function of a first trusted time value received by the device from the trusted authority during a first communication session;calculating a first time offset value corresponding to a difference between a second trusted time value and a second calculated time value, wherein the second trusted time value is received by the device from the trusted authority during a second communication session, andwherein the second calculated time value corresponds to a point in time when the second trusted time value is received by the device, and wherein the second calculated time value is a function of the first trusted time value; andcalculating an elapsed time value corresponding to a difference between a third calculated time value and a revised first calculated time value, wherein the third calculated time value corresponds to a point in time when the device attempts use of the content for a second occasion, and wherein the third calculated time value is a function of the second trusted time value, andwherein the revised first calculated time value corresponds to a combination of the first calculated time value and the first time offset value. 12. A system for controlling the use of content and adapted for communication with a trusted authority external to the system, the system comprising: a device having a processing unit capable of executing software routines, andprogramming logic executed by the processing unit, wherein the programming logic is operable with the processing unit to perform steps comprising: calculating a first calculated time value corresponding to a point in time when the content is used by the device on a first occasion, wherein the first calculated time value is a function of a first trusted time value received by the device from the trusted authority during a first communication session;calculating a first time offset value corresponding to a difference between a second trusted time value and a second calculated time value, wherein the second trusted time value is received by the device from the trusted authority during a second communication session, andwherein the second calculated time value corresponds to a point in time when the second trusted time value is received by the device, and wherein the second calculated time value is a function of the first trusted time value; andcalculating an elapsed time value corresponding to a difference between a third calculated time value and a revised first calculated time value, wherein the third calculated time value corresponds to a point in time when the device attempts use of the content for a second occasion, and wherein the third calculated time value is a function of the second trusted time value, andwherein the revised first calculated time value corresponds to a combination of the first calculated time value and the first time offset value. 13. A method of monitoring time comprising: receiving a first trusted time value from a trusted authority external to a client;combining, using a central processing unit (CPU), a time offset value with the first trusted time value to obtain a calculated time value, wherein the time offset value is a function of a difference between a second counter value and a first counter value, the second counter value corresponding to a point in time when the calculated time value is being obtained, and the first counter value corresponding to a point in time corresponding to the first trusted time value; andpermitting the use of content if a difference between the calculated time value and a second time value is less than a first predetermined time period, the second time value corresponding to a point in time when the client most recently established communication with the trusted authority. 14. The method of claim 13, further comprising securely storing the first trusted time value, the first counter value, and the second time value. 15. The method of claim 13 wherein receiving the first trusted time value includes receiving the first trusted time value from the trusted authority while the trusted authority is in communication with the client via a network, and wherein combining the time offset value with the first trusted time value includes combining the time offset value with the first trusted time value at a point in time when the client is not in communication with the trusted authority. 16. The method of claim 13 wherein receiving the first trusted time value includes receiving the first trusted time value from the trusted authority while the trusted authority is in communication with the client via a network, the method further comprising: securely storing the first trusted time value;terminating communications with the trusted authority;receiving a third trusted time value from the trusted authority after a second predetermined time period has elapsed since a point in time when communications with the trusted authority was terminated; andsecurely storing the third trusted time value. 17. The method of claim 16 wherein the second predetermined time period is less than the first predetermined time period. 18. A method of monitoring time comprising: receiving a first trusted time value from a trusted authority external to a client while the trusted authority is in communication with the client via a network;securely storing, using a central processing unit (CPU), the first trusted time value;terminating communications with the trusted authority after the first trusted time value is received;receiving a second trusted time value from the trusted authority after a first predetermined time period has elapsed since a point in time when communications with the trusted authority was terminated;combining a time offset value with the second trusted time value to obtain a calculated time value when the client is not in communication with the trusted authority, wherein the time offset value is a function of a difference between a second counter value and a first counter value;wherein the first counter value corresponding to a point in time corresponding to the second trusted time value, and wherein the second counter value corresponds to a point in time when the calculated time value is being obtained; andpermitting the use of content if a difference between the calculated time value and a third time value is less than a second predetermined time period, wherein the third time value corresponds to a point in time when the client most recently established communication with the trusted authority. 19. The method of claim 18 further comprising securely storing second trusted time value, the first counter value and the third time value. 20. The method of claim 18 wherein the first predetermined time period is less than the second predetermined time period. 21. An article of manufacture for controlling the use of content and for use by a device having a processing unit, the device being adapted to receive data from a trusted authority external to the device and being further adapted to produce a plurality of counter values, the article of manufacture comprising: at least one non-transitory, tangible computer usable media including at least one computer program embedded therein, the at least one computer program being adapted to cause the device to perform: receiving a first trusted time value from the trusted authority;combining a time offset value with the first trusted time value to obtain a calculated time value, wherein the time offset value is a function of a difference between a second counter value and a first counter value, the second counter value corresponding to a point in time when the calculated time value is being obtained, and the first counter value corresponding to a point in time corresponding to the first trusted time value; andpermitting use of the content if a difference between the calculated time value and a second time value is less than a first predetermined time period, the second time value corresponding to a point in time when the device most recently established communication with the trusted authority. 22. A system for controlling the use of content, the system comprising: a device having a processing unit capable of executing software routines, the device being adapted to receive data from a trusted authority external to the device and to produce a plurality of counter values, andprogramming logic executed by the processing unit, wherein the programming logic is operable with the processing unit to perform steps comprising: receiving a first trusted time value from the trusted authority;combining a time offset value with the first trusted time value to obtain a calculated time value, wherein the time offset value is a function of a difference between a second counter value and a first counter value, the second counter value corresponding to a point in time when the calculated time value is being obtained, and the first counter value corresponding to a point in time corresponding to the first trusted time value; andpermitting use of the content if a difference between the calculated time value and a second time value is less than a first predetermined time period, the second time value corresponding to a point in time when the device most recently established communication with the trusted authority.