Communication system and communication device

Patent metadata

Field	Value
Publication number	US-10142311-B2
Application number	US-201514965683-A
Country	US
Kind code	B2
Filing date	Dec 10, 2015
Priority date	Feb 26, 2015
Publication date	Nov 27, 2018
Grant date	Nov 27, 2018

Abstract

Devices between which packets are transmitted and received include mutually corresponding packet counters. The same random number value is given to the packet counters as their initial values and the packet counters are updated with packet transmission/reception. The transmission-side device generates a MAC value, draws out part thereof on the basis of a counted value of its own packet counter, sets it as a divided MAC value, generates a packet by adding the value to a message and transmits the packet onto a network. The reception-side device generates a MAC value on the basis of the message in the received packet, draws out part thereof on the basis of a counted value of its own packet counter, compares the part with the divided MAC value in the received packet and thereby performs message authentication.

First claim

What is claimed is:

1. A communication system, comprising:
a first device and a second device which are mutually coupled via a network so as to transmit and receive packets over the network,
wherein the first device and the second device respectively include a first packet counter and a second packet counter,
wherein a same random number value is given to the first and second packet counters as initial values of the first and second packet counters, and the first and second packet counters are respectively updated by the first device and the second device in association with each transmission and each reception of the packets by using values generated from performing a same lossy compression function on counted values of the first and the second packet counters as increment values,
wherein, when a message is to be transmitted to the second device, the first device generates a message authentication code on a basis of the message, draws out a part of the message authentication code on a frame position of some bits which are designated on a basis of a counted value of the first packet counter, sets the drawn-out part of the message authentication code as a divided message authentication code, generates a packet which includes the message and the divided message authentication code, and transmits the packet which includes the message and the divided message authentication code to the second device over the network, and
wherein, when the packet has been received from the first device, the second device generates another message authentication code on a basis of the message included in the received packet, draws out a part of the another message authentication code on the frame position of some bits which are designated on a basis of a counted value of the second packet counter, compares the drawn-out part of the another message authentication code with the divided message authentication code included in the received packet and performs a message authentication on the basis of a result of the comparison.

2. The communication system according to claim 1 , wherein one of the first and second devices generates the same random number value, sets the generated same random number value as an initial value of a respective packet counter of the one of the first and second devices, converts the same random number value into a cipher by encryption, and transmits the cipher to the other of the first and second devices, and the other of the first and second devices decodes the cipher to restore the same random number value, and sets the restored same random number value as the initial value of a respective packet counter of the other of the first and second devices.

3. The communication system according to claim 2 , wherein the encryption conforms to a common key cryptosystem.

4. The communication system according to claim 3 , wherein the first and second devices execute challenge/response authentication which conforms to a public key cryptosystem before transmitting and receiving the same random number value for an encryption of values of the first and second packet counters.

5. The communication system according to claim 1 , wherein, when the packet has been received, the part which has been drawn out of the another message authentication code which has been generated on a basis of the message included in the received packet on a basis of the counted value of the second packet counter by the second device is set as a central bit array, wherein the second device further draws a plurality of bit arrays of the another message authentication code out of positions based on counted values in a plurality of message authentication code (MAC) values, the plurality of MAC values are generated on a basis of a plurality of counted values respectively corresponding to received packets ranging from a first received packet which has been received earlier than a received packet associated with “i” packets (“i” is an integer) to a second received packet to be received later than a received packet associated with “j” packets (“j” is an integer), and wherein the second device compares each of the central bit array and the plurality of bit arrays with the divided message authentication code included in the received packet and authenticates the received packet as a valid packet when at least one bit array matches the divided message authentication code.

6. The communication system according to claim 5 , wherein the “i” and the “j” are set to “1s”.

7. The communication system according to claim 1 , wherein at least one of the first and second devices includes a hardware security module.

8. The communication system according to claim 1 , wherein the first and second devices include respectively electronic control units, and the network includes an on-vehicle network.

9. A communication system, comprising;
a first device and a second device which are mutually coupled via a network so as to transmit and receive packets over the network,
wherein the first device and the second device respectively include a first packet counter and a second packet counter which are respectively updated the first device and the second device in association with each transmission and each reception of the packets by using values generated from performing a same lossy compression function on counted values of the first and the second packet counters as increment values,
wherein, when a message is to be transmitted to the second device, the first device generates a message authentication code on a basis of the message, draws out a part of the message authentication code on a frame position of some bits which are designated on a basis of a counted value of the first packet counter, sets the drawn-out part of the message authentication code as a divided message authentication code, generates a packet which includes the message and the divided message authentication code and transmits the packet to the second device over the network,
wherein, when the packet has been received from the first device, the second device generates another message authentication code on a basis of the message included in the received packet, draws out a part of the another message authentication code on the frame position of some bits which are designated on a basis of a counted value of the second packet counter and sets the drawn-out part of the another message authentication code on the basis of the counted value of the second packet counter as a central bit array,
wherein the second device further draws a plurality of bit arrays of the another message authentication code out of positions based on counted values in a plurality of message authentication code (MAC) values, the plurality of MAC values are generated on a basis of a plurality of counted values respectively corresponding to received packets ranging from a first received packet which has been received earlier than a received packet associated with “i” packets (“i” is an integer) to a second received packet to be received later than a received packet associated with “j” packets (“j” is an integer), and
wherein the second device compares each of the central bit array and the plurality of bit arrays with the divided message authentication code included in the received packet and authenticates the received packet as a valid packet when at least one bit array matches the divided message authentication code.

10. The communication system according to claim 9 , wherein the “i” and the “j” are set to “1s”.

11. A communication device, which is coupled with another communication device which includes a first packet counter via a network, so as to transmit and receive packets to and from the another communication device via the network and aut

Assignees

• Renesas Electronics Corp

Inventors

• Oshida Daisuke

Classifications

• H04L69/324

  in the data link layer [OSI layer 2], e.g. HDLC · 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

• H04L63/08 Primary

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

• H04L2209/84

  Vehicles · CPC title

• H04L9/3242

  involving keyed hash functions, e.g. message authentication codes [MACs], CBC-MAC or HMAC · CPC title