Paper 2025/867

Side Channel Analysis in Homomorphic Encryption

Baraq Ghaleb, Edinburgh Napier University
William J Buchanan
Abstract

Homomorphic encryption provides many opportunities for privacy-aware processing, including with methods related to machine learning. Many of our existing cryptographic methods have been shown in the past to be susceptible to side channel attacks. With these, the implementation of the cryptographic methods can reveal information about the private keys used, the result, or even the original plaintext. An example of this includes the processing of the RSA exponent using the Montgomery method, and where 0's and 1's differ in their processing time for modular exponentiation. With FHE, we typically use lattice methods, and which can have particular problems in their implementation in relation to side channel leakage. This paper aims to outline a range of weaknesses within FHE implementations as related to side channel analysis. It outlines a categorization for side-channel analysis, some case studies, and mitigation strategies.

Metadata
Available format(s)
PDF
Category
Attacks and cryptanalysis
Publication info
Preprint.
Keywords
homomorphic encryptionside channelmitigation
Contact author(s)
b Ghaleb @ napier ac uk
b buchanan @ napier ac uk
History
2025-05-19: approved
2025-05-16: received
See all versions
Short URL
https://ia.cr/2025/867
License
Creative Commons Attribution
CC BY

BibTeX

@misc{cryptoeprint:2025/867,
      author = {Baraq Ghaleb and William J Buchanan},
      title = {Side Channel Analysis in Homomorphic Encryption},
      howpublished = {Cryptology {ePrint} Archive, Paper 2025/867},
      year = {2025},
      url = {https://eprint.iacr.org/2025/867}
}
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