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SCA-LDPC: A Code-Based Framework for Key-Recovery Side-Channel Attacks on Post-Quantum Encryption Schemes

Guo, Qian LU ; Nabokov, Denis LU ; Nilsson, Alexander LU orcid and Johansson, Thomas LU orcid (2023)
Abstract
Whereas theoretical attacks on standardized crypto primitives rarely lead to actual practical attacks, the situation is different for side-channel attacks. Improvements in the performance of side-channel attacks are of utmost importance.

In this paper, we propose a framework to be used in key-recovery side-channel attacks on CCA-secure post-quantum encryption schemes. The basic idea is to construct chosen ciphertext queries to a plaintext checking oracle that collects information on a set of secret variables in a single query. Then a large number of such queries is considered, each related to a different set of secret variables, and they are modeled as a low-density parity-check code (LDPC code). Secret variables are finally... (More)
Whereas theoretical attacks on standardized crypto primitives rarely lead to actual practical attacks, the situation is different for side-channel attacks. Improvements in the performance of side-channel attacks are of utmost importance.

In this paper, we propose a framework to be used in key-recovery side-channel attacks on CCA-secure post-quantum encryption schemes. The basic idea is to construct chosen ciphertext queries to a plaintext checking oracle that collects information on a set of secret variables in a single query. Then a large number of such queries is considered, each related to a different set of secret variables, and they are modeled as a low-density parity-check code (LDPC code). Secret variables are finally determined through efficient iterative decoding methods, such as belief propagation, using soft information. The utilization of LDPC codes offers efficient decoding, source compression, and error correction benefits. It has been demonstrated that this approach provides significant improvements compared to previous work by reducing the required number of queries, such as the number of traces in a power attack.

The framework is demonstrated and implemented in two different cases. On one hand, we attack implementations of HQC in a timing attack, lowering the number of required traces considerably compared to attacks in previous work. On the other hand, we describe and implement a full attack on a masked implementation of Kyber using power analysis. Using the ChipWhisperer evaluation platform, our real-world attacks recover the long-term secret key of a first-order masked implementation of Kyber-768 with an average of only 12 power traces. (Less)
Please use this url to cite or link to this publication:
author
; ; and
organization
publishing date
type
Working paper/Preprint
publication status
published
subject
publisher
Cryptology ePrint Archive
project
Side channels on software implementations of post-quantum cryptographic algorithms
language
English
LU publication?
yes
id
f3ff3afc-d507-4784-bce7-3a6866c76f0a
alternative location
https://eprint.iacr.org/2023/294
date added to LUP
2023-03-29 09:58:56
date last changed
2023-09-23 02:52:51
@misc{f3ff3afc-d507-4784-bce7-3a6866c76f0a,
  abstract     = {{Whereas theoretical attacks on standardized crypto primitives rarely lead to actual practical attacks,  the situation is different for side-channel attacks. Improvements in the performance of side-channel attacks are of utmost importance.<br/><br/>In this paper, we propose a framework to be used in key-recovery side-channel attacks on CCA-secure post-quantum encryption schemes. The basic idea is to construct chosen ciphertext queries to a plaintext checking oracle that collects information on a set of secret variables in a single query. Then a large number of such queries is considered, each related to a different set of secret variables, and they are modeled as a low-density parity-check code (LDPC code). Secret variables are finally determined through efficient iterative decoding methods, such as belief propagation, using soft information. The utilization of LDPC codes offers efficient decoding, source compression, and error correction benefits. It has been demonstrated that this approach provides significant improvements compared to previous work by reducing the required number of queries, such as the number of traces in a power attack.<br/><br/>The framework is demonstrated and implemented in two different cases. On one hand, we attack implementations of HQC in a timing attack, lowering the number of required traces considerably compared to attacks in previous work. On the other hand, we describe and implement a full attack on a masked implementation of Kyber using power analysis. Using the ChipWhisperer evaluation platform, our real-world attacks recover the long-term secret key of a first-order masked implementation of Kyber-768 with an average of only 12 power traces.}},
  author       = {{Guo, Qian and Nabokov, Denis and Nilsson, Alexander and Johansson, Thomas}},
  language     = {{eng}},
  note         = {{Preprint}},
  publisher    = {{Cryptology ePrint Archive}},
  title        = {{SCA-LDPC: A Code-Based Framework for Key-Recovery Side-Channel Attacks on Post-Quantum Encryption Schemes}},
  url          = {{https://eprint.iacr.org/2023/294}},
  year         = {{2023}},
}