Method and apparatus for performing cross-authentication based on secret information

Patent metadata

Field	Value
Publication number	US-9960915-B2
Application number	US-201514790599-A
Country	US
Kind code	B2
Filing date	Jul 2, 2015
Priority date	Mar 17, 2015
Publication date	May 1, 2018
Grant date	May 1, 2018

Abstract

A method of performing cross-authentication in a vehicle controller interworking with an external device includes: generating a random number S and transmitting the random number S to the external device according to an authentication request message received from the external device; generating a variable i using a first function having the random number S as a parameter; generating a first session key Ks using a second function having the variable i and a pre-stored secret key K as parameters; receiving a first response key from the external device; generating a second response key using a third function having the random number S, the variable i and the first session key Ks as parameters; and authenticating the external device based on whether the first response key is equal to the second response key.

First claim

What is claimed is:

1. A method of performing cross-authentication in a vehicle controller interworking with an external device via a wired or wireless connection, the method comprising:
generating, by a random number generator of the vehicle controller, a random number S and transmitting the random number S to the external device in response to an authentication request message received from the external device;
generating, by a repeat count generator of the vehicle controller, a variable i using a first function having the random number S as a parameter, wherein a random number R and the random number S are set as parameters of the first function to generate the variable i when the random number R is included in the authentication request message, and the variable i is calculated using a function for cyclic-shifting the random number R by a specified number of bits of the random number S;
generating, by a session key generator of the vehicle controller, a first session key Ks using a second function having the variable i and a pre-stored secret key K as parameters;
receiving, at the vehicle controller, a first response key from the external device;
generating, by a response key generator of the vehicle controller, a second response key using a third function having the random number S, the variable i and the first session key Ks as parameters;
authenticating, by an authenticator of the vehicle controller, the external device based on whether the first response key is equal to the second response key; and
granting, by the vehicle controller, the external device access to the vehicle controller when the external device is authenticated.

2. The method according to claim 1 , wherein the variable i is calculated by:
i=f 1 ( R, S )= L S ( R )+ S mod 16,
where L S (R) is the function for cyclic-shifting the random number R by the specified number of bits of the random number S.

3. The method according to claim 1 , wherein the random number S is further used to generate the first session key Ks.

4. The method according to claim 3 , wherein the first session key Ks is generated by performing a bitwise XOR operation with respect to a first value generated by performing an XOR operation of the secret key K and the random number S and a second value generated by cyclic-shifting the first value by the variable i.

5. The method according to claim 4 , wherein the first value is generated by repeatedly concatenating the random number S by a specified number of bits of the secret key K and then performing the bitwise XOR operation.

6. The method according to claim 1 , wherein the random number R is further used to generate the second response key when the random number R is included in the authentication request message.

7. The method according to claim 6 , wherein the second response key is calculated by:
f 3 ( i, K S , R, S )= g ( i+m, K S , R, S )=[g 3 ( w i+m ( K S ), g 2 ( g 1 ( R⊕S ))))] i+m ,
where m is a minimum repeat count predetermined based on a security level required for the vehicle controller.

8. The method according to claim 7 , wherein R⊕S is calculated by:
R⊕S=l 7 ∥l 6 ∥l 5 ∥l 4 ∥l 3 ∥l 2 ∥l 1 ∥l 0 ,

where l j is a value obtained by dividing a result of performing a bitwise XOR operation of the random number R and the random number S by 4 bits.

9. The method according to claim 8 , wherein g 1 (R⊕S) is calculated by:
g 1 ( R⊕S )= h ( l 7 )∥ h ( l 6 )∥ h ( 5 )∥ h ( l 4 )∥ h ( l 3 )∥ h ( l 2 )∥ h ( l 1 )∥ h ( l 0 ),

where h(l j ) is a substitution operation.

10. The method according to claim 9 , wherein h(l j ) is calculated by:
(l j )={9, 4, 10, 11, 13, 1, 8, 5, 6, 2, 0, 3, 12, 14, 15, 7}.

11. The method according to claim 9 , wherein g 2 (g 1 (R⊕S) is calculated by a product of a pre-defined 4×4 matrix and 4-bit h(l j ).

12. The method according to claim 11 , wherein g 2 (g 1 (R⊕S) is calculated by:

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Assignees

• Hyundai Motor Co Ltd
• Kia Motors Corp
• Univ Chosun Iacf
• Snu R&Db Foundation
• Kia Motors Corp

Inventors

• Ahn Hyun Soo
• Jung Ho Jin
• Woo Jun Young
• Kim Ho Youn
• Lee Kang Seok
• Yoon Jong Yoon
• No Jong Seon
• Kim Young Sik

Classifications

• H04L9/0869 Primary

  involving random numbers or seeds · CPC title

• H04L9/3273

  for mutual authentication (network architectures or network communication protocols for achieving mutual authentication in a packet data network H04L63/0869) · CPC title

• H04L2209/84

  Vehicles · CPC title

• H04L63/083

  using passwords (cryptographic mechanisms or cryptographic arrangements for entity authentication using a predetermined code H04L9/3226) · CPC title

• H04L67/12

  specially adapted for proprietary or special-purpose networking environments, e.g. medical networks, sensor networks, networks in vehicles or remote metering networks · CPC title