IP Library Granted Patent US 9,838,201
Granted Patent B2
US 9,838,201 · App. 14/882,230 · Granted Dec 5, 2017

Secure key store derivation and management from a single secure root key

View Patent ↗
Loading inventors, assignments & file history…
Monitor This Case
Get email alerts when status or documents change.
Order Certified Copies
Most orders are placed with the USPTO same day — all within 24 business hours.
Order via The Patent Place →
Pre-filled with this patent's details
Quick Facts
Patent No.
US 9,838,201
App. No.
14/882,230
Granted
Dec 5, 2017
Kind
B2
Abstract

A root key of a computing device that is typically “burned” into the device hardware at time of manufacture is used to establish a master key and if desired a Transport Layer Security pre-shaped key, a WiFi configuration key, and application verification keys. The keys established from the root key are stored in a region of flash memory, and this region of flash memory is then encrypted using a random encryption code.

Claims (53)

1. Device comprising:

at least one computer memory that is not a transitory signal or software per se and that comprises instructions executable by at least one processing circuitry to:

access a root key of a computing device;

use the root key of the computing device to establish at least one derived key selected from: a master key component SM, or a Transport Layer Security pre-shared key component ST, or a Wifi configuration key component SW, or an application verification key component SA;

store the at least one derived key in a first region of a memory, the first region being less than 100% of a total storage area of the memory; and

encrypt the first region using a random encryption code, wherein the random encryption code includes at least one of:

advanced encryption standard (AES) XEX encryption mode;

Liskov, Rivest, Wagner (LRW) encryption;

cipher block chaining-mask-cipher block chaining (CMC) encryption;

electronic codebook-mask-electronic codebook (EME) encryption.

2. The device of claim 1 , wherein the random encryption code includes advanced encryption standard (AES) XEX encryption mode.

3. The device of claim 2 , wherein the AES XEX encryption mode has tweak and ciphertext stealing (XTS) having a first tweak value equal to a key number of the derived key and a second tweak value equal to an AES block number.

4. The device of claim 1 , wherein the random encryption code includes Liskov, Rivest, Wagner (LRW) encryption.

5. The device of claim 1 , wherein the random encryption code includes cipher block chaining-mask-cipher block chaining (CMC) encryption.

6. The device of claim 1 , wherein the random encryption code includes electronic codebook-mask-electronic codebook (EME) encryption.

7. The device of claim 1 , wherein the instructions are executable to:

upon first boot or derived key reset, generate a mask L; and

establish an AES-XTS key using L, the AES-XTS key being used to encrypt the first region of the memory.

8. The device of claim 1 , comprising the at least one processing circuitry coupled to the at least one computer memory.

9. The device of claim 1 , wherein the first region has a memory size of thirty two kilobytes (32 kB).

10. The device of claim 1 , wherein the derived key includes at least two of: the master key component SM, the Transport Layer Security pre-shared key component ST, the Wifi configuration key component SW, the application verification key component SA.

11. The device of claim 1 , wherein the derived key includes the master key component SM.

12. The device of claim 1 , wherein the derived key includes the Transport Layer Security pre-shared key component ST.

13. The device of claim 1 , wherein the derived key includes the Wifi configuration key component SW.

14. The device of claim 1 , wherein the derived key includes the application verification key component SA.

15. Method comprising:

accessing a root key H of a computing device, the root key H being permanently stored on a secure hardware storage of the computing device;

using the root key H to establish a master key M by combining the root key H with a pseudorandom benign key split, represented as follows:

M=kdf (H, SM), where kdf=key derivation function, H=root key, SM=master key component;

using the master key to encrypt a Transport Layer Security pre-shared key (TLS_PSK) component ST;

using the TLS_PSK component ST to establish an encrypted communication channel with at least one paired device;

storing the master key component SM and the TLS_PSK component ST in an encrypted region of a memory; and

encrypting the first region using a random encryption code, wherein the random encryption code includes at least one of:

advanced encryption standard (AES) XEX encryption mode;

Liskov, Rivest, Wagner (LRW) encryption;

cipher block chaining-mask-cipher block chaining (CMC) encryption;

electronic codebook-mask-electronic codebook (EME) encryption.

16. The method of claim 15 , wherein the random encryption code includes advanced encryption standard (AES) XEX encryption mode.

17. The method of claim 16 , comprising:

upon first boot or derived key reset, generating a mask L; and

establishing an AES-XTS key using the mask L, the AES-XTS key being used to encrypt the first region of the memory.

18. Apparatus comprising:

at least one processing circuitry; and

at least one memory accessible to the at least one processing circuitry and comprising instructions executable by the at least one processing circuitry for:

deriving, from a hard-coded, unchangeable root key H, a master key M;

encrypting at least one communication key component using the master key M but not storing the master key M in an encrypted region of memory;

storing the communication key component encrypted by the master key M in the encrypted region of memory for use of the communication key component to establish a secure communication channel with a paired device;

storing a component SM of the master key M in the encrypted region of memory, the component SM of the master key M defined by: M=kdf (H, SM), where kdf=key derivation function;

encrypting the encrypted region of memory using a random encryption code wherein the random encryption code includes at least one of:

advanced encryption standard (AES) XEX encryption mode;

Liskov, Rivest, Wagner (LRW) encryption;

cipher block chaining-mask-cipher block chaining (CMC) encryption;

electronic codebook-mask-electronic codebook (EME) encryption.

Assignments (3)
MERGER Recorded Mar 30, 2020
From: SONY INTERACTIVE ENTERTAINMENT AMERICA LLC
To: SONY INTERACTIVE ENTERTAINMENT LLC
Reel/Frame 053323/0567 →
CHANGE OF NAME Recorded May 5, 2016
From: SONY COMPUTER ENTERTAINMENT AMERICA LLC
To: SONY INTERACTIVE ENTERTAINMENT AMERICA LLC
Reel/Frame 038630/0154 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Oct 13, 2015
From: COTTA, BRYAN
To: SONY COMPUTER ENTERTAINMENT AMERICA LLC
Reel/Frame 036785/0451 →