Method for safeguarding the information security of data transmitted via a data bus and data bus system

Patent metadata

Field	Value
Publication number	US-10686587-B2
Application number	US-201615576940-A
Country	US
Kind code	B2
Filing date	May 19, 2016
Priority date	May 27, 2015
Publication date	Jun 16, 2020
Grant date	Jun 16, 2020

Abstract

A method for saving the information security of data transmitted by a databus, in which the data to be transmitted via the databus from a transmitter (ECU s ) to at least one receiver (ECU R ) are divided into data blocks (M 0 . . . M n ) before being sent off, wherein the data blocks (M 0 . . . M n ) are encrypted and/or signed block by block by means of a sponge construction for forming a cryptological hash function, utilizing a key, and cipher blocks (C 0 . . . C n ) generated in this way are transmitted via the databus to the at least one receiver. The invention also relates to a corresponding databus system.

First claim

The invention claimed is:

1. A method for preserving information security of data transmitted by a databus, comprising:
generating cipher blocks by dividing the data to be transmitted via the databus from a transmitter to at least one receiver into data blocks before being transmitted, wherein the data blocks are at least one of encrypted and signed, block by block, using a sponge construction that forms a cryptological hash function, utilizing a key, and transmitting the generated cipher blocks via the databus to the at least one receiver, and
wherein an internal state of the sponge construction has a rate and a capacity, wherein a content of a cipher block is utilized as the rate of a respectively following internal state of the sponge construction.

2. The method as claimed in claim 1 , wherein the block-by-block encryption of the data blocks and block-by-block generation of the cipher blocks takes place during a phase of inclusion of the data blocks.

3. The method as claimed in claim 1 , wherein, following the encryption of the data blocks and generation of the cipher blocks, a signature is generated using the sponge construction on the basis of the data blocks to be transmitted and of the key and is transmitted via the databus.

4. The method as claimed in claim 1 , wherein an initialization state of the sponge construction is initialized with the key.

5. The method as claimed in claim 1 , wherein a cipher block is determined from a rate of an internal state using a data block.

6. The method as claimed in claim 5 , wherein the sponge construction has at least one sponge function which maps an internal state onto a following internal state, the sponge function being formed by using at least one substitution permutation network.

7. The method as claimed in claim 6 , wherein the substitution permutation network is implemented by a block-cipher.

8. The method as claimed in claim 7 , wherein the block-cipher is Advanced Encryption Standard.

9. The method as claimed in claim 5 , wherein a first part of an internal state of a sponge function is supplied as data to be encrypted and a second part of the internal state of the sponge function is supplied as key.

10. The method as claimed in claim 9 , wherein a second part of an internal state of the sponge construction is supplied to a substitution permutation network of the sponge function as data to be encrypted and the first part of the internal state is supplied to the substitution permutation network as key.

11. The method as claimed in claim 1 , wherein a cipher block is determined by utilizing a data block from a rate obtained from the key or a rate calculated using a sponge function, using Exclusive-OR logic.

12. The method as claimed in claim 1 , wherein the transmission of the cipher blocks via the databus occurs following the encryption of all data blocks and formation of the signature or block-by-block in each case following the encryption of an individual data block.

13. The method as claimed in claim 1 , wherein the length of a data block corresponds to the length of a data frame or to the length of the payload data of a data frame of a basic databus protocol of the databus or the length of a data frame of a databus protocol of the databus corresponds to a multiple of the length of a data block.

14. A databus system for preserving information security of data transmitted by a databus, comprising:
a transmitter,
at least one receiver,
and at least one communication means for communication between the transmitter and the at least one receiver,
the databus system configured to:
generate cipher blocks by dividing the data to be transmitted via the databus from the transmitter to the at least one receiver into data blocks before being transmitted, wherein the data blocks are at least one of encrypted and signed, block by block, using a sponge construction that forms a cryptological hash function, utilizing a key, and transmit the generated cipher blocks via the databus to the at least one receiver, and
wherein an internal state of the sponge construction has a rate and a capacity, wherein a content of a cipher block is utilized as the rate of a respectively following internal state of the sponge construction.

15. The system as claimed in claim 14 , wherein the block-by-block encryption of the data blocks and block-by-block generation of the cipher blocks takes place during a phase of the inclusion of the data blocks.

16. The system as claimed in claim 14 , wherein, following the encryption of the data blocks and generation of the cipher blocks, a signature is generated using the sponge construction on the basis of the data blocks to be transmitted and of the key and is transmitted via the databus.

17. The system as claimed in claim 14 , wherein an initialization state of the sponge construction is initialized with the key.

18. The system as claimed in claim 14 , wherein a cipher block is determined from a rate of an internal state using a data block.

19. The system as claimed in claim 14 , wherein a cipher block is determined by utilizing a data block from a rate obtained from the key or a rate calculated using a sponge function, using Exclusive-OR logic.

Assignees

• Continental Teves Ag & Co Ohg

Inventors

• Molter Hans Gregor
• Stoettinger Marc

Classifications

• H04L9/0637 Primary

  Modes of operation, e.g. cipher block chaining [CBC], electronic codebook [ECB] or Galois/counter mode [GCM] · CPC title

• H04L63/061

  for key exchange, e.g. in peer-to-peer networks (cryptographic mechanisms or cryptographic arrangements for key agreement H04L9/0838) · CPC title

• H04L9/0631 Primary

  Substitution permutation network [SPN], i.e. cipher composed of a number of stages or rounds each involving linear and nonlinear transformations, e.g. AES algorithms · CPC title

• H04L9/3239

  involving non-keyed hash functions, e.g. modification detection codes [MDCs], MD5, SHA or RIPEMD · CPC title

• H04L9/3242

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