Magnifying side-channel leakage of lattice-based cryptosystems with chosen ciphertexts: the case study of Kyber

Zhuang Xu, Owen Michael Pemberton, Sujoy Sinha Roy, David Oswald, Wang Yao, Zhiming Zheng

Research output: Contribution to journalArticlepeer-review

271 Downloads (Pure)


Lattice-based cryptography, as an active branch of post-quantum cryptography (PQC), has drawn great attention from side-channel analysis researchers in recent years. Despite the various side-channel targets examined in previous studies, detail on revealing the secret-dependent information efficiently is less studied. In this paper, we propose adaptive EM side-channel attacks with carefully constructed ciphertexts on Kyber, which is a finalist of NIST PQC standardization project. We demonstrate that specially chosen ciphertexts allow an adversary to modulate the leakage of a target device and enable full key extraction with a small number of traces through simple power analysis. Compared to prior research, our techniques require fewer traces and avoid building complex templates. We practically evaluate our methods using both a reference implementation and the ARM-specific implementation in pqm4 library. For the reference implementation, we target the leakage of the output of the inverse NTT computation and recover the full key with only four traces. For the pqm4 implementation, we develop a message-recovery attack that leads to extraction of the full secret key with between eight and 960 traces, depending on the compiler optimization level. We discuss the relevance of our findings to other lattice-based schemes and explore potential countermeasures.
Original languageEnglish
Article number9591340
Number of pages14
JournalIEEE Transactions on Computers
Early online date27 Oct 2021
Publication statusE-pub ahead of print - 27 Oct 2021


  • Computers
  • Cryptography
  • Elliptic curve cryptography
  • Quantum computing
  • Resistance
  • Search problems
  • Side-channel attacks


Dive into the research topics of 'Magnifying side-channel leakage of lattice-based cryptosystems with chosen ciphertexts: the case study of Kyber'. Together they form a unique fingerprint.

Cite this