Authenticated communication between multiple entities

• US 7,831,827 B2
• Filed: 01/12/2004
• Issued: 11/09/2010
• Est. Priority Date: 12/02/2002
• Status: Expired due to Fees

• Current Assignee: Memjet Technology Ltd. (Memjet Limited)
• Original Assignee: Silverbrook Research Pty Limited
• Inventors: Walmsley, Simon Robert
• Primary Examiner(s): Barron, Jr.; Gilberto
• Assistant Examiner(s): ALMEIDA, DEVIN E
• Application Number:
  US10/754,938
• Publication Number:
  US 20040193880A1
• Time in Patent Office: 2,493 Days
• Field of Search: 713/168, 380/2
• US Class Current: 713/168
• CPC Class Codes: B41J 2/04505 aiming at correcting alignment
• CPC Class Codes: B41J 2/04508 aiming at correcting other parameters
• CPC Class Codes: B41J 2/0451 for detecting failure, e.g. clogging, malfunctioning actuator
• CPC Class Codes: B41J 2/04528 aiming at warming up the head
• CPC Class Codes: B41J 2/04541 Specific driving circuit
• CPC Class Codes: B41J 2/04543 Block driving
• CPC Class Codes: B41J 2/04563 detecting head temperature; Ink temperature
• CPC Class Codes: B41J 2/04573 Timing; Delays
• CPC Class Codes: B41J 2/04586 controlling heads of a type not covered by groups B41J2/04575 - B41J2/04585, or of an undefined type
• CPC Class Codes: B41J 2202/20 Modules
• CPC Class Codes: G06F 21/554 involving event detection and direct action
• CPC Class Codes: G06F 21/57 Certifying or maintaining trusted computer platforms, e.g. secure boots or power-downs, version controls, system software checks, secure updates or assessing vulnerabilities
• CPC Class Codes: G06F 21/575 Secure boot
• CPC Class Codes: G06F 21/64 Protecting data integrity, e.g. using checksums, certificates or signatures
• CPC Class Codes: G06F 21/71 to assure secure computing or processing of information
• CPC Class Codes: G06F 21/73 by creating or determining hardware identification, e.g. serial numbers
• CPC Class Codes: G06F 21/74 operating in dual or compartmented mode, i.e. at least one secure mode
• CPC Class Codes: G06F 21/78 to assure secure storage of data address-based protection against unauthorised use of memory G06F12/14; record carriers for use with machines and with at least a part designed to carry digital markings G06K19/00
• CPC Class Codes: H03K 5/1252 Suppression or limitation of noise or interference specially adapted for transmission systems H04B15/00, H04L25/08
• CPC Class Codes: H04N 1/405 Halftoning, i.e. converting the picture signal of a continuous-tone original into a corresponding signal showing only two levels
• CPC Class Codes: Y10S 707/99933 : Query processing, i.e. searching
• CPC Class Codes: Y10S 707/99939 : Privileged access
• CPC Class Codes: Y10T 29/49401 : Fluid pattern dispersing device making, e.g., ink jet

Abstract

A method of passing validated information along a series of entities, the series of entities including a source entity, a series of at least one intermediate entity, and a target entity, wherein each of the entities shares a validation parameter with its immediately neighboring entity or entities in the series, the method comprising the steps, commencing in the source entity, of: (a) in the current entity, generating a validation code for the information, the validation code being based on the validation parameter shared between the current entity and the next entity in the series; (b) outputting the validation code; c) receiving the validation code in the next entity in the series and making that entity the current entity; (d) verifying the information via the validation code in the current entity using the validation parameter required to verify it; (e) repeating steps (a) to (d) until the last intermediate entity in the series has output the validation code it generated; and (f) receiving the validation code in the target entity and verifying the information via the validation code and the validation parameter required to verify it.

Claims

1. A method of passing validated information along a series of entities, the series of entities including a source entity, a plurality of intermediate entities, and a target entity, wherein each of the entities shares a validation parameter with its immediately neighbouring entity or entities in the series, the method comprising the steps of:

(a) in the source entity, generating a validation code for the information, the validation code being based on the validation parameter shared between the source entity and an intermediate entity of the plurality of intermediate entities;

(b) outputting the validation code;

(c) receiving the validation code in the intermediate entity and making that intermediate entity a current entity;

(d) verifying the information via the validation code in the current entity using the validation parameter required to verify it;

(e) in the current entity, generating a validation code for the information, the validation code being based on the validation parameter shared between the current entity and a next entity in the series;

(f) outputting the validation code;

(g) receiving the validation code in the next entity in the series and making that entity the current entity;

(h) verifying the information via the validation code in the current entity using the validation parameter required to verify it; and

(j) repeating steps (e) to (h) until the current entity in steps (g) and (h) is the target entity,

wherein the next entity in the series in steps (e) to (g) includes at least another intermediate entity of the plurality of intermediate entities, and

non-valid information is periodically passed to the target entity and whether the non-valid information is valid or non-valid is verified in the target entity.

2. A method according to claim 1, wherein steps (b) and (f) include the substep of outputting the information.

3. A method according to claim 1 or claim 2, wherein steps (c) and (g) include receiving the information and using it during the verification.

4. A method according to claim 1, further including a controller in contact with at least some of the entities, the controller being configured to pass the information and/or the validation codes between adjacent entities in the series.

5. A method according to claim 4, wherein step (a) is performed in response to an instruction issued by the controller.

6. A method according to claim 5, wherein the instruction includes a request for the information upon which the validation is to be performed.

7. A method according to claim 1, wherein the validation code is a digital signature produced by a digital signature function using the information and the validation parameter as operands.

8. A method according to claim 7, wherein the validation parameter is a key.

9. A method according to claim 8, wherein the key is a symmetric key.

10. A method according to claim 7, wherein the validation parameter is an asymmetric key-pair, and the public and private components of the key-pair are in respective neighboring entities in the series.

11. A method according to claim 8 or 10, wherein the validation code is a digital signature generated with a digital signature function using the key or key-pair component, the information and at least one nonce as inputs.

12. A method according to claim 11, wherein the at least one nonce is generated in the current entity in response to an instruction issued by the neighbouring entity of the current entity closer to the target entity.

13. A method according to claim 12, wherein the at least one nonce is randomly, pseudo-randomly or arbitrarily generated number.

14. A method according to claim 11, wherein the at least one nonce is supplied to the current entity in an instruction issued by the neighbouring entity of the current entity closer to the target entity.

15. A method according to claim 14, wherein the nonce is randomly, pseudo-randomly or arbitrarily generated number.

16. A method according to claim 1, wherein a different validation parameter is used for the validation step performed at any two adjacent entities.

17. A method according to claim 1, wherein at least one of the entities is an integrated circuit.

18. A method according to claim 1, wherein the target entity is a printer controller integrated circuit.

19. A method according to claim 1, wherein the source entity is a printer controller integrated circuit.

20. A method according to claim 1, wherein either the source entity or the target entity is a printer controller integrated circuit and the at least one intermediate entity is a verification chip associated with the printer controller.

21. A method according to claim 4, wherein the controller is a printer controller integrated circuit.

22. A method according to claim 4, where one of the entities is the controller.

23. A method according to claim 20, wherein the printer controller has a relatively unique identity and the verification chip includes a key based on the unique identity.

24. A method according to claim 1, wherein the source or target entity is an integrated circuit associated with a package that contains ink.