Providing Authenticated Communications to a Replaceable Printer Component

• US 20110075189A1
• Filed: 05/29/2008
• Published: 03/31/2011
• Est. Priority Date: 05/29/2008
• Status: Active Grant

• Current Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Original Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Inventors: Refstrup, Jacob Grundtvig
• Granted Patent: US 9,875,365 B2
• Time in Patent Office: Days
• US Class Current: 358/1.14
• CPC Class Codes: G06F 21/608 Secure printing

Abstract

A replaceable printer component includes a first memory device and a communication link. The first memory device stores a first secret. The communication link is configured to communicatively link the first memory device to a printer controller when the replaceable printer component is installed in a printing system. The printing system includes a second memory device storing a second secret. The second memory device is communicatively linked to the printer controller. The first memory device is configured to authenticate communications between the first memory device and the printer controller based on the first secret and the second secret.

Claims

1. A replaceable printer component comprising:

a first memory device storing a first secret; and

a communication link configured to communicatively link the first memory device to a printer controller when the replaceable printer component is installed in a printing system,

wherein the printing system comprises a second memory device storing a second secret, the second memory device communicatively linked to the printer controller, and

wherein the first memory device is configured to authenticate communications between the first memory device and the printer controller based on the first secret and the second secret.

2. The replaceable printer component of claim 1, wherein the first secret is derived from the second secret.

3. The replaceable printer component of claim 1, wherein the first memory device is configured to generate a session-key identifier and a first session-key based on the first secret and provide the session-key identifier to the second memory device in response to a request, and

wherein the second memory device is configured to generate a second session-key based on the session-key identifier and the second secret.

4. The replaceable printer component of claim 3, wherein the first memory device is configured to receive a read or write request from the printer controller, the read or write request including a first message authentication code calculated using the second session-key, and

wherein the first memory device is configured to calculate a second message authentication code based on the read or write request and the first session-key, and perform the read or write request in response to the second message authentication code matching the first message authentication code.

5. The replaceable printer component of claim 4, wherein the first memory device is configured to deny the read or write request and to mark the first session-key as invalid in response to the second message authentication code not matching the first message authentication code.

6. The replaceable printer component of claim 3, wherein the first memory device is configured to generate a different session-key identifier and session-key in response to each request.

7. The replaceable printer component of claim 1, wherein the first memory device is tamper resistant, and

wherein the second memory device is tamper resistant.

8. The replaceable printer component of claim 1, wherein the replaceable printer component comprises one of an inkjet cartridge, an inkjet printhead assembly, a toner cartridge, and an ink supply.

9. The replaceable printer component of claim 1, wherein the replaceable printer component comprises a peripheral device of the printing system.

10. A replaceable printer component comprising:

means for storing a first secret key in the replaceable printer component;

means for installing the replaceable printer component into a printing system, the printing system comprising means for storing a second secret key; and

means for authenticating communications between the replaceable printer component and the printing system based on the first secret key and the second secret key.

11. The replaceable printer component of claim 10, wherein the first secret key is derived from the second secret key.

12. The replaceable printer component of claim 10, wherein the means for authenticating the communications comprises:

means for requesting a session-key identifier from the replaceable printer component;

means for generating the session-key identifier and a first session-key within the replaceable printer component based on the first secret key in response to the request; and

means for generating a second session-key within the printing system based on the session-key identifier and the second secret key.

13. The replaceable printer component of claim 12, wherein the means for authenticating the communications further comprises:

means for calculating a first message authentication code using the second session-key within the printing system for a read or write request to the replaceable printer component;

means for issuing the read or write request including the first message authentication code to the replaceable printer component;

means for calculating a second message authentication code for the read or write request using the first session-key within the replaceable printer component; and

means for performing the read or write request in response to the second message authentication code matching the first message authentication code.

14. The replaceable printer component of claim 13, wherein the means for authenticating the communications further comprises:

means for denying the read or write request and marking the first session-key as invalid in response to the second message authentication code not matching the first message authentication code.

15. A replaceable printer component comprising:

a first memory device storing a first secret; and

a communication link configured to communicatively link the first memory device to a printer controller when the replaceable printer component is installed in a printing system,

wherein the first memory device is configured to, in response to a request, generate a session-key identifier and a first session-key based on the first secret and transmit the session-key identifier over the communication link to the printer controller, and

wherein the session-key identifier and the first session-key are used to authenticate communications between the first memory device and the printer controller.