Vehicular entropy for random number generation

Patent metadata

Field	Value
Publication number	US-9912475-B2
Application number	US-201514805470-A
Country	US
Kind code	B2
Filing date	Jul 22, 2015
Priority date	Jul 22, 2015
Publication date	Mar 6, 2018
Grant date	Mar 6, 2018

Abstract

A method is provided for producing cryptographic keys, while a vehicle is in operation, for use in secure vehicle communications. The method may include obtaining unique entropy data from an entropy source based on dynamically changing, transient variables related to the operation of the vehicle, optionally in a driving mode. The method may include seeding a random number generator with the unique entropy data to generate at least one random number. A plurality of cryptographic keys are generated based on the at least one random number. A secure communication exchange may be established using the plurality of cryptographic keys. A non-transitory computer-readable medium is also provided having instructions embodied thereon that, when executed by a processor, perform the above operations as an algorithm in a vehicle.

First claim

What is claimed is:

1. A method for producing cryptographic keys while a vehicle is in operation for use in secure vehicle communications, the method comprising:
obtaining unique entropy data from an entropy source of dynamically changing, transient measured variables of the operation of the vehicle while the vehicle is in an operating mode;
seeding a random number generator with the unique entropy data to generate at least one random number;
generating a plurality of cryptographic keys from the at least one random number; and
establishing a secure communication exchange using the plurality of cryptographic keys,
wherein the unique entropy data is data of a measurement of a physical property of the vehicle selected from the group consisting of: an angular speed of a wheel, a revolutions per minute (RPM) value of an engine, a level of compression of a shock, a speed of a blower motor, a measurement of cabin noise, a mileage or distance reading, a fill level of a fuel tank, and combinations thereof.

2. The method according to claim 1 , wherein the unique entropy data is obtained from concatenating or truncating at least a portion of data taken from a plurality of different entropy sources and collected in a pool of data, and the step of seeding the random number generator with unique entropy data comprises randomly selecting data from the pool of data as a seed.

3. A method for providing a seed for generating a random number during vehicle operation and enabling secure data communications, the method comprising:
receiving a request to initiate a secure communication exchange;
obtaining unique entropy data from an entropy source of dynamically changing, transient measured variables of the operation of the vehicle while the vehicle is in an operating mode;
seeding a random number generator with the unique entropy data to generate at least one random number;
generating a set of paired cryptographic keys from the at least one random number;
transmitting a first cryptographic key to a first unit;
transmitting a second cryptographic key to a second unit;
establishing the secure communication exchange using the first and second cryptographic keys; and
transmitting data between the first unit and the second unit using the secure communication exchange,
wherein the unique entropy data is data of a measurement of a physical property of the vehicle selected from the group consisting of: an angular speed of a wheel, a revolutions per minute (RPM) value of an engine, a level of compression of a shock, a speed of a blower motor, a measurement of cabin noise, a mileage or distance reading, a fill level of a fuel tank, and combinations thereof.

4. The method according to claim 3 , wherein the unique entropy data is obtained from concatenating or truncating at least a portion of data taken from a plurality of different entropy sources and collected in a pool of data, and the step of seeding the random number generator with unique entropy data comprises randomly selecting data from the pool of data as a seed.

5. The method according to claim 3 , wherein the request to initiate the secure communication exchange is from a device external to the vehicle.

6. The method according to claim 5 , further comprising obtaining authorization for the request to initiate the secure communication exchange from an operator or passenger of the vehicle prior to establishing the secure communication exchange.

7. The method according to claim 5 , wherein the device is a remote processor or module.

8. The method according to claim 5 , wherein the device is associated with an autonomous vehicle.

9. The method according to claim 3 , wherein the request to initiate the secure communication is from an internal vehicle system, sub-system, or module.

10. The method according to claim 3 , further comprising configuring at least one of the first and second cryptographic keys to expire upon conclusion of the transmission of data using the secure communication exchange.

11. A non-transitory computer-readable medium having instructions embodied thereon that, when executed by a processor, perform operations in a vehicle, the operations comprising:
receiving a request to initiate a secure communication exchange;
obtaining unique entropy data from an entropy source having dynamically changing, transient measured variables while the vehicle is in an operating mode;
providing the unique entropy data to a random number generator as a seed to generate at least one random number;
generating a set of paired cryptographic keys from the at least one random number;
transmitting a first cryptographic key to a first unit;
transmitting a second cryptographic key to a second unit;
establishing the secure communication exchange using the first and second cryptographic keys; and
transmitting data between the first unit and the second unit using the secure communication exchange,
wherein the operations comprise obtaining unique entropy data of a measurement of a physical property of the vehicle selected from the group consisting of: an angular speed of a wheel, a revolutions per minute (RPM) value of an engine, a level of compression of a shock, a speed of a blower motor, a measurement of cabin noise, a mileage or distance reading, a fill level of a fuel tank, and combinations thereof.

12. The non-transitory computer-readable medium as recited in claim 11 , wherein the operations comprise concatenating or truncating at least a portion of unique entropy data from a plurality of different entropy sources that is collected in a pool of data, and the step of providing the unique entropy data to a random number generator as the seed comprises randomly selecting data from the pool of data as the seed.

13. The non-transitory computer-readable medium as recited in claim 11 , wherein the operational step of receiving the request to initiate the secure communication exchange comprises receiving the request from a device external to the vehicle.

14. The non-transitory computer-readable medium as recited in claim 11 , wherein the operations further comprise obtaining authorization for the request to initiate the secure communication exchange from an operator or passenger of the vehicle prior to establishing the secure communication exchange.

Assignees

• Toyota Eng & Mfg North America

Inventors

• Schmidt Eric R
• Pierfelice Jeffrey E

Classifications

• H04L9/0861 Primary

  Generation of secret information including derivation or calculation of cryptographic keys or passwords · CPC title

• H04L9/0662 Primary

  with particular pseudorandom sequence generator · CPC title

• H04L2209/84

  Vehicles · CPC title

• H04L9/0869

  involving random numbers or seeds · CPC title