Data protection in a pre-operation system environment based on an embedded key of an embedded controller

Patent metadata

Field	Value
Publication number	US-11429722-B2
Application number	US-201816479737-A
Country	US
Kind code	B2
Filing date	Jan 29, 2018
Priority date	Jan 29, 2018
Publication date	Aug 30, 2022
Grant date	Aug 30, 2022

Abstract

An example system with a pre-OS (Operating System) environment, the pre-OS environment includes a private memory that is isolated from a processor of the system. The pre-OS environment also includes an embedded controller (EC) coupled to the private memory, where the EC includes an embedded key. The EC is to execute instructions to generate an encryption key based on the embedded key; generate a signature key; obtain data; produce an integrity-verification tag based on a hash of the obtained data, where the hash employs the signature key; encrypt the obtained data based on the encryption key; store the encrypted data in the private memory; and store the integrity-verification tag in the private memory in association with the stored encrypted data.

First claim

What is claimed is:

1. A system with a pre-OS (Operating System) environment, the pre-OS environment comprises:
a private memory that is isolated from a processor of the system; and
an embedded controller (EC) coupled to the private memory, wherein the EC includes an embedded key;
the EC to execute instructions to:
generate an encryption key based on the embedded key;
generate a signature key based on the embedded key;
obtain data;
produce an integrity-verification tag based on a hash of the obtained data, wherein the hash employs the signature key;
encrypt the obtained data based on the encryption key;
store the encrypted data in the private memory in a first memory block, wherein the private memory includes a solid-state non-volatile computer storage medium that employs NOR logic gates;
store the integrity-verification tag in the private memory in association with the stored encrypted data, wherein the private memory includes data sets that are used by the EC during a system's initial boot sequence and hardware initialization, and wherein the EC compares a second integrity-verification tag with the integrity-verification tag when the EC reads the stored encrypted data for integrity verification; and
store a subsequent encrypted data set in the first memory block, wherein any bit “1” of a first addressable location is changed to “0” to indicate alteration of the stored encrypted data.

2. The system of claim 1 , wherein the encrypted data stored in the private memory is accessible only to the EC.

3. The system of claim 1 , wherein the embedded key is inaccessible and unattainable outside of the EC.

4. The system of claim 1 , wherein the integrity-verification tag includes a hash message authentication code (HMAC) that is based upon a keyed cryptographic hash function.

5. The system of claim 4 , wherein the EC reads the HMAC based on the signature key.

6. A non-transitory machine-readable storage medium encoded with instructions executable by a processor of a system, the machine-readable storage medium comprising instructions to:
generate an encryption key based upon an embedded key installed into an embedded controller (EC) of the system;
generate a signature key based on the embedded key;
obtain data;
produce an integrity-verification tag based on a function of the obtained data, wherein the function employs the signature key;
encrypt the obtained data based on the encryption key;
store the encrypted data in memory in a first memory block, wherein the memory includes a solid-state non-volatile computer storage medium that employs NOR logic gates;
store the integrity-verification tag in the memory in association with the stored encrypted data, wherein the memory includes data sets that are used by the EC during a system's initial boot sequence and hardware initialization, and wherein the EC compares a second integrity-verification tag with the integrity-verification tag when the EC reads the stored encrypted data for integrity verification; and
store a subsequent encrypted data set in the first memory block, wherein any bit “1” of a first addressable location is changed to “0” to indicate alteration of the stored encrypted data.

7. The non-transitory machine-readable storage medium of claim 6 , wherein the encryption key is based upon a combination of an initialization vector and a randomly generated number, the randomly generated number being seeded from the embedded key.

8. The non-transitory machine-readable storage medium of claim 7 further comprising instructions to update the encryption key by incrementing the initialization vector used in a previous encryption of data.

9. The non-transitory machine-readable storage medium of claim 6 , wherein the embedded key is inaccessible and unattainable outside of the EC.

10. The non-transitory machine-readable storage medium of claim 6 , wherein the function is a keyed cryptographic hash function.

11. A non-transitory machine-readable storage medium encoded with instructions executable by an embedded controller (EC) of a pre-OS (Operating System) environment, the machine-readable storage medium comprising instructions to:
generate an encryption key based upon an embedded key of the EC, wherein the embedded key is inaccessible and unattainable outside the EC;
generate a signature key based on the embedded key;
obtain data;
produce an integrity-verification tag based on a hash of the obtained data, wherein the hash employs the signature key;
encrypt the obtained data based on the encryption key;
store the encrypted data in memory in a first memory block, wherein the memory includes a solid-state non-volatile computer storage medium that employs NOR logic gates;
store the integrity-verification tag in the memory in association with the stored encrypted data, wherein the memory includes data sets that are used by the EC during a system's initial boot sequence and hardware initialization, and wherein the EC compares a second integrity-verification tag with the integrity-verification tag when the EC reads the stored encrypted data for integrity verification; and
store a subsequent encrypted data set in the first memory block, wherein any bit “1” of a first addressable location is changed to “0” to indicate alteration of the stored encrypted data.

12. The non-transitory machine-readable storage medium of claim 11 , the machine-readable storage medium further comprising instructions to update an initialization vector used, at least in part, to generate another encryption key.

13. The non-transitory machine-readable storage medium of claim 11 , wherein the integrity-verification tag includes a hash message authentication code (HMAC) that is based upon a keyed cryptographic hash function.

Assignees

• Hewlett Packard Development Co

Inventors

• Jeansonne Jeffrey Kevin
• Braduke Rosilet Retnamoni
• Schiffman Joshua Serratelli
• Plaquin David

Classifications

• G06F21/575 Primary

  Secure boot · CPC title

• G06F21/577

  Assessing vulnerabilities and evaluating computer system security · CPC title

• G06F21/602

  Providing cryptographic facilities or services · CPC title

• G06F21/556

  involving covert channels, i.e. data leakage between processes (inhibiting the analysis of circuitry or operation with measures against power attack G06F21/755) · CPC title

• G06F2221/0751

  Physics · mapped topic