Benchmarking Large Language Models for Cryptanalysis and Side-Channel Vulnerabilities

Utsav Maskey, Chencheng Zhu, Usman Naseem


Abstract
Recent advancements in Large Language Models (LLMs) have transformed natural language understanding and generation, leading to extensive benchmarking across diverse tasks. However, cryptanalysis—a critical area for data security and its connection to LLMs’ generalization abilities remains underexplored in LLM evaluations. To address this gap, we evaluate the cryptanalytic potential of state‐of‐the‐art LLMs on ciphertexts produced by a range of cryptographic algorithms. We introduce a benchmark dataset of diverse plaintexts—spanning multiple domains, lengths, writing styles, and topics—paired with their encrypted versions. Using zero‐shot and few‐shot settings along with chain‐of‐thought prompting, we assess LLMs’ decryption success rate and discuss their comprehension abilities. Our findings reveal key insights into LLMs’ strengths and limitations in side‐channel scenarios and raise concerns about their susceptibility to under-generalization related attacks. This research highlights the dual‐use nature of LLMs in security contexts and contributes to the ongoing discussion on AI safety and security.
Anthology ID:
2025.findings-emnlp.1082
Volume:
Findings of the Association for Computational Linguistics: EMNLP 2025
Month:
November
Year:
2025
Address:
Suzhou, China
Editors:
Christos Christodoulopoulos, Tanmoy Chakraborty, Carolyn Rose, Violet Peng
Venue:
Findings
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
19849–19865
Language:
URL:
https://preview.aclanthology.org/author-page-yu-wang-polytechnic/2025.findings-emnlp.1082/
DOI:
10.18653/v1/2025.findings-emnlp.1082
Bibkey:
Cite (ACL):
Utsav Maskey, Chencheng Zhu, and Usman Naseem. 2025. Benchmarking Large Language Models for Cryptanalysis and Side-Channel Vulnerabilities. In Findings of the Association for Computational Linguistics: EMNLP 2025, pages 19849–19865, Suzhou, China. Association for Computational Linguistics.
Cite (Informal):
Benchmarking Large Language Models for Cryptanalysis and Side-Channel Vulnerabilities (Maskey et al., Findings 2025)
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PDF:
https://preview.aclanthology.org/author-page-yu-wang-polytechnic/2025.findings-emnlp.1082.pdf
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