License: Creative Commons Attribution 4.0 International license (CC BY 4.0)
When quoting this document, please refer to the following
DOI: 10.4230/LIPIcs.ITC.2022.4
URN: urn:nbn:de:0030-drops-164826
URL: http://dagstuhl.sunsite.rwth-aachen.de/volltexte/2022/16482/
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Döttling, Nico ; Dujmovic, Jesko

Maliciously Circuit-Private FHE from Information-Theoretic Principles

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LIPIcs-ITC-2022-4.pdf (0.9 MB)

Abstract

Fully homomorphic encryption (FHE) allows arbitrary computations on encrypted data. The standard security requirement, IND-CPA security, ensures that the encrypted data remain private. However, it does not guarantee privacy for the computation performed on the encrypted data. Statistical circuit privacy offers a strong privacy guarantee for the computation process, namely that a homomorphically evaluated ciphertext does not leak any information on how the result of the computation was obtained. Malicious statistical circuit privacy requires this to hold even for maliciously generated keys and ciphertexts. Ostrovsky, Paskin and Paskin (CRYPTO 2014) constructed an FHE scheme achieving malicious statistical circuit privacy.
Their construction, however, makes non-black-box use of a specific underlying FHE scheme, resulting in a circuit-private scheme with inherently high overhead.
This work presents a conceptually different construction of maliciously circuit-private FHE from simple information-theoretical principles. Furthermore, our construction only makes black-box use of the underlying FHE scheme, opening the possibility of achieving practically efficient schemes. Finally, in contrast to the OPP scheme in our scheme, pre- and post-homomorphic ciphertexts are syntactically the same, enabling new applications in multi-hop settings.

BibTeX - Entry

@InProceedings{dottling_et_al:LIPIcs.ITC.2022.4,
  author =	{D\"{o}ttling, Nico and Dujmovic, Jesko},
  title =	{{Maliciously Circuit-Private FHE from Information-Theoretic Principles}},
  booktitle =	{3rd Conference on Information-Theoretic Cryptography (ITC 2022)},
  pages =	{4:1--4:21},
  series =	{Leibniz International Proceedings in Informatics (LIPIcs)},
  ISBN =	{978-3-95977-238-9},
  ISSN =	{1868-8969},
  year =	{2022},
  volume =	{230},
  editor =	{Dachman-Soled, Dana},
  publisher =	{Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
  address =	{Dagstuhl, Germany},
  URL =		{https://drops.dagstuhl.de/opus/volltexte/2022/16482},
  URN =		{urn:nbn:de:0030-drops-164826},
  doi =		{10.4230/LIPIcs.ITC.2022.4},
  annote =	{Keywords: Fully Homomorphic Encryption, FHE, Homomorphic Encryption, Oblivious Transfer, Malicious Statistical Circuit Privacy, Multi-Hop, Information Theory, Cryptography}
}

Keywords: Fully Homomorphic Encryption, FHE, Homomorphic Encryption, Oblivious Transfer, Malicious Statistical Circuit Privacy, Multi-Hop, Information Theory, Cryptography
Collection: 3rd Conference on Information-Theoretic Cryptography (ITC 2022)
Issue Date: 2022
Date of publication: 30.06.2022

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