Method for protecting a computer system from side-channel attacks

Patent metadata

Field	Value
Publication number	US-2017141912-A1
Application number	US-201615347299-A
Country	US
Kind code	A1
Filing date	Nov 9, 2016
Priority date	Nov 18, 2015
Publication date	May 18, 2017
Grant date	—

Abstract

A method for protecting a computer system from side-channel attacks when using an encryption or decryption method for data packets of a data stream, wherein interruptions in the encryption or decryption method are generated by a random generator, where further computing operations are applied during the interruptions to already encrypted or decrypted data packets of the data stream or to data packets of the data stream which are yet to be encrypted or decrypted to generate random noise in the power consumption of the computer system.

First claim

What is claimed is:

1 . A method for protecting a computer system from side-channel attacks when using an encryption or decryption method for data packets of a data stream, the method comprising:
generating interruptions in the encryption or decryption method via a random generator; and applying further computing operations to already encrypted or decrypted data packets of the data stream or to data packets of the data stream which are yet to be encrypted or decrypted during the generated interruptions to generate random noise in power consumption of the computer system.

2 . The method as claimed in claim 1 , wherein the further computing operations are part of an error-correction method.

3 . The method as claimed in claim 1 , wherein the further computing operations are part of an algorithm for message authentication via a message authentication code.

4 . The method as claimed in claim 2 , wherein the further computing operations are part of an algorithm for message authentication via a message authentication code.

5 . The method as claimed in claim 1 , wherein, in cases of encryption, the data stream is initially subjected to the encryption method and then subjected to the further computing operations.

6 . The method as claimed in claim 2 , wherein, in cases of encryption, the data stream is initially subjected to the encryption method and then subjected to the further computing operations.

7 . The method as claimed in claim 3 , wherein, in cases of encryption, the data stream is initially subjected to the encryption method and then subjected to the further computing operations.

8 . The method as claimed in claim 5 , wherein the further computing operations comprise an error-correction method.

9 . The method as claimed in claim 1 , wherein, in cases of decryption, the data stream is subjected initially subjected to the further computing operations and then subjected to the decryption method.

10 . The method as claimed in claim 2 , wherein, in cases of decryption, the data stream is subjected initially subjected to the further computing operations and then subjected to the decryption method.

11 . The method as claimed in claim 3 , wherein, in cases of decryption, the data stream is subjected initially subjected to the further computing operations and then subjected to the decryption method.

12 . The method as claimed in claim 5 , wherein the further computing operations comprise an error-correction method.

13 . The method as claimed in one of claim 1 , wherein a start and finish of the further computing operations are controlled by the encryption or decryption method.

14 . The method as claimed in claim 1 , wherein, if the further computing operations are finished, but the encryption or decryption method is unfinished, the interruptions generated by the encryption or decryption method are filled with computing operations based on random data.

15 . The method as claimed in claim 2 , wherein an error-correction method is performed with random data which are generated by the random generator.

16 . The method as claimed in claim 14 , wherein an error-correction method is performed with random data which are generated by the random generator.

17 . A computer system, comprising:
at least one encryption or decryption unit; a further computing unit arranged in series with the at least one encryption or decryption unit with respect to a data stream; and a random generator configured to generate interruptions in an encryption or decryption method in the encryption or decryption unit; wherein the encryption or decryption unit is operatively connected to the further computing unit such that, during the interruptions, the further computing unit applies further computing operations to already encrypted or decrypted data packets of the data stream or to data packets of the data stream which are yet to be encrypted or decrypted.

18 . The computer system as claimed in claim 17 , wherein the random generator is operatively connected to the further computing unit such that, in an event that the further computing operations are completed, but the encryption or decryption method is not yet finished, the interruptions generated by the encryption or decryption method are filled with computing operations of the further computing unit based on random data from the random generator.

19 . The computer system as claimed in claim 17 , wherein the computer system comprises a field-programmable gate array and the encryption or decryption unit and further computing unit are formed as a soft core or hard core.

20 . A non-transitory computer program product encoded with a program which is directly loadable into a computing unit of a computer system which, when executed by the computing unit, provides protection of the computer system from side-channel attacks when using an encryption or decryption method for data packets of a data stream, the computer program comprising:
program code generating interruptions in the encryption or decryption method via a random generator; and program code for applying further computing operations to already encrypted or decrypted data packets of the data stream or to data packets of the data stream which are yet to be encrypted or decrypted during the generated interruptions to generate random noise in power consumption of the computer system.

Assignees

• Siemens Ag Oesterreich

Inventors

• Cech Christian
• Matschnig Martin
• Pitu Ciprian-Leonard

Classifications

• H04L9/32

  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

• H04L9/003 Primary

  for power analysis, e.g. differential power analysis [DPA] or simple power analysis [SPA] · CPC title

• H04L9/0662

  with particular pseudorandom sequence generator · CPC title

• H04L9/30

  Public key, i.e. encryption algorithm being computationally infeasible to invert or user's encryption keys not requiring secrecy · CPC title

• H04L9/06

  the encryption apparatus using shift registers or memories for block-wise {or stream} coding, e.g. DES systems {or RC4; Hash functions; Pseudorandom sequence generators} · CPC title