Paper 2025/1983

SCORE: A SlotToCoeff Optimization for Real-Vector Encryption in CKKS

Tim Seuré, University of Luxembourg
Abstract

We present SCORE, a modified version of the SlotToCoeff operation tailored to encrypted real vectors in the CKKS scheme, where SCORE stands for “SlotToCoeff Optimization for Real-Vector Encryption”. This approach accelerates CKKS bootstrapping algorithms that employ the SlotToCoeff operation as their final step, provided the inputs are encryptions of real vectors. We demonstrate its utility through proof-of-concept implementations for two such algorithms: the conventional bootstrapping algorithm and the SPRU algorithm. Our results indicate notable performance gains of up to 2× compared to the original formulations of the algorithms.

Metadata
Available format(s)
PDF
Category
Public-key cryptography
Publication info
Preprint.
Keywords
Homomorphic EncryptionFully Homomorphic EncryptionCKKSBootstrappingRing-LWE
Contact author(s)
tim seure @ uni lu
History
2025-10-29: approved
2025-10-23: received
See all versions
Short URL
https://ia.cr/2025/1983
License
Creative Commons Attribution
CC BY

BibTeX

@misc{cryptoeprint:2025/1983,
      author = {Tim Seuré},
      title = {{SCORE}: A {SlotToCoeff} Optimization for Real-Vector Encryption in {CKKS}},
      howpublished = {Cryptology {ePrint} Archive, Paper 2025/1983},
      year = {2025},
      url = {https://eprint.iacr.org/2025/1983}
}
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