Clock synchronization

• US 10,110,368 B2
• Filed: 12/04/2015
• Issued: 10/23/2018
• Est. Priority Date: 12/08/2014
• Status: Active Grant

• Current Assignee: Diebold Nixdorf, Incorporated
• Original Assignee: Diebold Nixdorf, Incorporated
• Inventors: Ray, Gregory S., McCortney, David R., Varn, Kenneth
• Primary Examiner(s): Higa, Brendan Y
• Application Number:
  US14/959,955
• Publication Number:
  US 20160164663A1
• Time in Patent Office: 1,054 Days
• CPC Class Codes: G06F 1/12 Synchronisation of different clock signals provided by a plurality of clock generators
• CPC Class Codes: G06F 1/14 Time supervision arrangements, e.g. real time clock
• CPC Class Codes: G06F 21/31 User authentication
• CPC Class Codes: G09C 1/00 Apparatus or methods whereby a given sequence of signs, e.g. an intelligible text, is transformed into an unintelligible sequence of signs by transposing the signs or groups of signs or by replacing them by others according to a predetermined system cryptographic typewriters G09C3/00
• CPC Class Codes: H04J 3/0635 Clock or time synchronisation in a network timer in protocols H04L69/28
• CPC Class Codes: H04J 3/0685 Clock or time synchronisation in a node; Intranode synchronisation
• CPC Class Codes: H04L 63/083 using passwords cryptographic mechanisms or cryptographic arrangements for entity authentication using a predetermined code H04L9/3226
• CPC Class Codes: H04L 7/0012 by comparing receiver clock with transmitter clock
• CPC Class Codes: H04L 9/3226 using a predetermined code, e.g. password, passphrase or PIN network architectures or network communication protocols for supporting authentication of entities using passwords in a packet data network H04L63/083
• CPC Class Codes: H04L 9/3234 involving additional secure or trusted devices, e.g. TPM, smartcard, USB or software token network architectures or network communication protocols for supporting authentication of entities using an additional device in a packet data network H04L63/0853

Abstract

In an example embodiment disclosed herein, a first clock is allowed to synchronize with a second clock as long as the time difference between the first and second clocks is less than a predefined limit. If the time difference between the clocks is not less than the predefined limit, the first clock does not synchronize with the second clock until a predefined activity has occurred.

Claims

1. An apparatus, comprising:

a clock;

a communication interface for communicating with a second clock; and

clock synchronization logic coupled with the clock and the communication interface;

a user interface coupled with the clock synchronization logic;

a housing; and

a second interface inside the housing, the second interface is not accessible until the user authentication has completed;

the clock synchronization logic allows the clock to synchronize with the second clock when the time difference between the clock and the second clock is less than a predetermined limit; and

the clock synchronization logic prevents the clock from synchronizing with the second clock when the time difference between the clock and the second clock is greater than the predetermined limit until a predefined event has been detected

wherein the predefined event is a user authentication received from a predetermined user via the user interface

wherein the predefined event further comprises an input to from the authenticated user to enter a predefined mode; and

wherein the input from the authenticated user to enter a predefined mode is received via the second interface.

2. The apparatus set forth in claim 1, wherein the second user authentication comprises receiving user authentication data via a token.

3. The apparatus set forth in claim 1, the second user interface comprises a keypad, wherein the user authentication comprises receiving a predefined code via the keypad.

4. The apparatus set forth in claim 1, the second user interface comprises a touch screen, wherein the user authentication comprises receiving a predefined code via the touch screen.

5. A tangible, non-transitory computer readable medium execution with instructions encoded thereon for execution by a process and when executed operable to:

determine a time difference between a first clock and a second clock;

determine a sum of changes to the first clock over a predefined time period;

synchronize the first clock with the second clock when the sum of changes is less than a predefined time limit; and

prevent the first clock from synchronizing with the second clock when the sum of changes is greater than the predetermined time limit until a predefined event has been detected.

6. The tangible, non-transitory computer readable medium execution set forth in claim 5, wherein the predefined event is a user authentication received from a predetermined user via the user interface.

7. The tangible, non-transitory computer readable medium execution set forth in claim 6, wherein the user authentication comprises receiving user authentication data via a token from a user interface.

8. The tangible, non-transitory computer readable medium execution set forth in claim 6, wherein the user authentication comprises receiving a predefined code via a keypad.

9. The tangible, non-transitory computer readable medium execution set forth in claim 6, wherein the user authentication comprises receiving a predefined code via a touch screen.

10. The tangible, non-transitory computer readable medium execution set forth in claim 6, wherein the predefined event further comprises an input to from the authenticated user to enter a predefined mode.

11. The tangible, non-transitory computer readable medium execution set forth in claim 10, the instructions are further operable to accept input from the authenticated user to enter a predefined mode after the user authentication has completed.

12. A method, comprising:

determining a time difference between a first clock and a second clock;

determining a sum of time changes to the first clock over a predefined time period responsive to the time difference between the first clock and the second clock being within a first predefined time limit;

synchronizing the first clock with the second clock responsive to the time difference between the first clock and the second clock being within the first predefined time limit and the sum of the time changes to the first clock over the first predefined time period are less than a second predefined limit;

preventing the first clock from synchronizing with the second clock responsive to the time difference is greater than the first predetermined time limit until a predefined event has been detected; and

preventing the first clock from synchronizing with the second clock responsive to the time difference between the first clock and the second clock being within the first predefined time limit and the sum of the time changes to the first clock over the first predefined time period is greater than the second predefined limit.

13. The method forth in claim 12, wherein the predefined event is a user authentication received from a predetermined user via the user interface.

14. The method set forth in claim 13, wherein the user authentication comprises receiving user authentication data via a token from a user interface.

15. The method set forth in claim 13, wherein the user authentication comprises receiving a predefined code via a keypad.

16. The method set forth in claim 13, wherein the user authentication comprises receiving a predefined code via a touch screen.

17. The method set forth in claim 13, wherein the predefined event further comprises an input to from the authenticated user to enter a predefined mode.