Creation and distribution of a secret value between two devices

• US 7,215,781 B2
• Filed: 12/22/2000
• Issued: 05/08/2007
• Est. Priority Date: 12/22/2000
• Status: Expired due to Fees

• Current Assignee: Intel Corporation
• Original Assignee: Intel Corporation
• Inventors: Grawrock, David W.
• Primary Examiner(s): Zand; Kambiz
• Assistant Examiner(s): Dinh; Minh
• Application Number:
  US09/747,238
• Publication Number:
  US 20020083332A1
• Time in Patent Office: 2,328 Days
• Field of Search: 713171-172, 713192-193, 713/200, 380/29, 380/44, 380/46, 380283-285, 380/262
• US Class Current: 380/283
• CPC Class Codes: G06F 21/445 by mutual authentication, e.g. between devices or programs
• CPC Class Codes: G06F 21/606 by securing the transmission between two devices or processes

Abstract

In general, one embodiment of the invention features a method comprising operations performed internally within a device. A first operation involves generating data for permanent storage in a protected area of internal memory of the device. This prevents subsequent modification of the data. A second operation involves producing a secret value being a combination of both the data and a short term value generated in response to a periodic event such as a power-up sequence of a platform employing the device.

Claims

1. A method comprising:

transmitting a first command from a second device being an input/output control hub (ICH) to a first device being a trusted platform module (TPM);

generating a long term value within the first device, the long term value generated upon detecting an initial power-up sequence and receipt of information from the second device;

permanently storing the long term value within a protected area of an internal memory of the first device;

providing the long term value to the second device communicatively coupled to the first device;

generating a short term value within the first device, the short term value is modified after each power cycle;

providing the short term value to the second device;

generating a secret value within the first device after each power cycle, the secret value being a combination of both the long term value and the short term value;

generating the secret value within the second device based on the long term value and the short term value; and

using the secret value to encrypt and decrypt data transmitted between the first device and the second device.

2. The method of claim 1, wherein the long term value is generated in response to an initial power-up sequence when the first device is in communication with the second device.

3. The method of claim 2, wherein prior generating the short term value, the method further comprises:

transmitting a second command from the second device to the first device.

4. The method of claim 1, wherein the combination is a result produced by successively performing a hashing operation on both the data and the short term value.