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

Patent metadata

Field	Value
Publication number	US-2016277189-A1
Application number	US-201514790599-A
Country	US
Kind code	A1
Filing date	Jul 2, 2015
Priority date	Mar 17, 2015
Publication date	Sep 22, 2016
Grant date	—

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, the method comprising:
generating 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 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.

2 . The method according to claim 1 , 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.

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

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

5 . The method according to claim 4 , 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.

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

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

8 . The method according to claim 7 , 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.

9 . The method according to claim 8 , 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.

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

where h(l j ) is a substitution operation.

11 . The method according to claim 10 , 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}.

12 . The method according to claim 10 , 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 ).

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

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Assignees

• Hyundai Motor Co Ltd
• Kia Motors Corp
• Industry-Academic Coop Found Chosun Univ
• Snu R&Db Foundation

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

• H04L9/0847

  involving identity based encryption [IBE] schemes · CPC title

• H04L9/32 Primary

  including means for verifying the identity or authority of a user of the system {or for message authentication, e.g. authorization, entity authentication, data integrity or data verification, non-repudiation, key authentication or verification of credentials} · CPC title

• H04L2209/84

  Vehicles · 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