Method of sequentially authenticating can packets using divided macs and apparatus for implementing the same

Patent metadata

Field	Value
Publication number	US-2016099926-A1
Application number	US-201514669301-A
Country	US
Kind code	A1
Filing date	Mar 26, 2015
Priority date	Oct 2, 2014
Publication date	Apr 7, 2016
Grant date	—

Abstract

A method of transmitting K messages using divided message authentication codes (MACs) in a controller area network (CAN) includes: generating a MAC using a first message and a specific MAC, performing a first operation with respect to j using j-th messages subsequent to the first message and a second MAC part of the generated MAC, performing a second operation with respect to j using a result of the performed first operation and a j-th subblock subsequent to a first MAC subblock among K MAC subblocks obtained by dividing a first MAC part of the generated MAC, transmitting the first message along with the first MAC subblock, and transmitting K-1 j-th messages in an order of j, each of the j-th messages being transmitted along with a j-th result of the performed second operation.

First claim

What is claimed is:

1 . A method of transmitting K messages using divided message authentication codes (MACs) in a controller area network (CAN), the method comprising:
generating a MAC using a first message and a specific MAC; performing a first operation with respect to j using j-th messages subsequent to the first message and a second MAC part of the generated MAC; performing a second operation with respect to j using a result of the performed first operation and a j-th subblock subsequent to a first MAC subblock among K MAC subblocks obtained by dividing a first MAC part of the generated MAC; transmitting the first message along with the first MAC subblock; and transmitting K-1 j-th messages in an order of j, wherein each of the j-th messages is transmitted along with a j-th result of the performed second operation.

2 . The method according to claim 1 , further comprising storing a K-th MAC subblock of the first MAC part as a specific MAC for generating MACs corresponding to K subsequent messages.

3 . The method according to claim 1 , wherein the performing of the first operation includes:
dividing each of the j-th messages into subblocks corresponding in number to a second value obtained by dividing a number obtained by subtracting a first value, which is a bit size of each MAC subblock, from 64 by the first value; dividing the second MAC part into subblocks corresponding in number to the second value; summing results of multiplying each of the divided subblocks of the j-th messages and each of the divided subblocks of the second MAC part, which are located in the same order; and acquiring lower bits of a number corresponding to the first value.

4 . The method according to claim 2 , wherein the performing of the second operation includes performing an exclusive OR (XOR) operation between the acquired lower bits and the j-th subblock with respect to j.

5 . The method according to claim 1 , wherein the specific MAC is a K-th MAC subblock of the first MAC part of a MAC corresponding to previously transmitted K messages.

6 . A controller for transmitting messages using divided message authentication codes (MACs) in a controller area network (CAN), the controller comprising:
a message management module configured to generate K messages; an authentication module configured to: i) generate a MAC using a first message of the K messages and a specific MAC, ii) perform a first operation with respect to j using j-th messages subsequent to the first message and a second MAC part of the generated MAC, and iii) perform a second operation with respect to j using a result of the performed first operation and a j-th subblock subsequent to a first MAC subblock among K MAC subblocks obtained by dividing a first MAC part of the generated MAC; and a transceiver module configured to transmit the first message along with the first MAC subblock and to transmit K-1 j-th messages in an order of j, wherein the transceiver module transmits each of the j-th messages along with a j-th result of the performed second operation.

7 . The controller according to claim 6 , wherein the authentication module is further configured to store a K-th MAC subblock of the first MAC part as a specific MAC for generating MACs corresponding to K subsequent messages.

8 . The controller according to claim 6 , wherein the authentication module is further configured to: divide each of the j-th messages into subblocks corresponding in number to a second value obtained by dividing a number obtained by subtracting a first value, which is a bit size of each MAC subblock, from 64 by the first value, ii) divide the second MAC part into subblocks corresponding in number to the second value, ii) sum results of multiplying each of the divided subblocks of the j-th messages and each of the divided subblocks of the second MAC part, which are located in the same order, and iv) acquire lower bits of a number corresponding to the first value, upon performing the first operation.

9 . The controller according to claim 7 , wherein the authentication module is further configured to perform an exclusive OR (XOR) operation between the acquired lower bits and the j-th subblock with respect to j.

10 . The controller according to claim 6 , wherein the specific MAC is a K-th MAC subblock of the first MAC part of a MAC corresponding to previously transmitted K messages.

11 . A method of receiving K messages using divided message authentication codes (MACs) in a controller area network (CAN), the method comprising:
receiving a first message and MAC data corresponding to the first message; generating a MAC using the first message and a specific MAC; comparing a first MAC subblock among K MAC subblocks divided by a first MAC part of the generated MAC to the MAC data corresponding to the first message; determining a temporary authentication state when the first MAC subblock divided by the first MAC part is equal to the MAC data; and determining authentication failure when the first MAC subblock divided by the first MAC part is not equal to the MAC data.

12 . The method according to claim 11 , further comprising:
receiving j-th messages subsequent to the first message in an order of j; performing a first operation with respect to j using the j-th messages and a second MAC part of the generated MAC; performing a second operation with respect to j using a result of the performed first operation and a j-th subblock subsequent to the first MAC subblock among the K MAC subblocks divided from the first MAC part of the generated MAC; sequentially comparing a j-th result of the performed second operation to j-th MAC data received along with each j-th message, with respect to j; and determining a final authentication state when MAC data received along with a most recent message and a last result of the performed second operation are equal to the sequentially compared result.

13 . The method according to claim 12 , further comprising storing a K-th MAC subblock of the first MAC part as a specific MAC for generating MACs corresponding to K subsequent messages.

14 . The method according to claim 12 , wherein the performing of the first operation includes:
dividing each of the j-th messages into subblocks corresponding in number to a second value obtained by dividing a number obtained by subtracting a first value, which is a bit size of each MAC subblock, from 64 by the first value; dividing the second MAC part into subblocks corresponding in number to the second value; summing results of multiplying each of the divided subblocks of the j-th messages and each of the divided subblocks of the second MAC part, which are located in the same order; and acquiring lower bits of a number corresponding to the first value.

15 . The method according to claim 14 , wherein the performing of the second operation includes performing an exclusive OR (XOR) operation between the acquired lower bits and the j-th subblock with respect to j.

16 . The method according to claim 12 , wherein the specific MAC is a K-th MAC subblock of the first MAC part of a MAC corresponding to previously received K messages.

17 . A controller for receiving messages using divided message authentication codes (MACs) in a controller area network (CAN), the controller comprising:
a transceiver module configured to receive a first message and MAC data corresponding to the first message; and an authentication module configured to: i) generate a MAC using the first message and a specific MAC, ii) compare a first MAC subblock among K MAC subblock

Assignees

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

Inventors

• Lee Byoung Wook
• Lee Chung Hi
• Yoo Ho
• Jung Ho Jin
• Ahn Hyun Soo
• Kim Ho Youn
• Moon Young Sik
• Woo Jun Young
• Kim Young Sik
• Lee Kang Seok
• No Jong Seon

Classifications

• H04L63/08 Primary

  for authentication of entities (cryptographic mechanisms or cryptographic arrangements for entity authentication H04L9/32) · CPC title

• H04L63/123

  received data contents, e.g. message integrity · 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

• H04L63/162

  at the data link layer · 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