Paper 2019/446

Backward Private DSSE: Alternative Formulations of Information Leakage and Efficient Constructions

Sanjit Chatterjee, Shravan Kumar Parshuram Puria, and Akash Shah

Abstract

Dynamic Searchable Symmetric Encryption ($\mathsf{DSSE}$), apart from providing support for search operation, allows a client to perform update operations on outsourced database efficiently. Two security properties, viz., forward privacy and backward privacy are desirable from a $\mathsf{DSSE}$ scheme. The former captures that the newly updated entries cannot be related to previous search queries and the latter ensures that search queries should not leak matching entries after they have been deleted. These security properties are formalized in terms of the information leakage that can be incurred by the respective constructions. Existing backward private constructions either have a non-optimal communication overhead or they make use of heavy cryptographic primitives. Our main contribution consists of three efficient backward private schemes that aim to achieve practical efficiency by using light weight symmetric cryptographic components only. In the process, we also revisit the existing definitions of information leakage for backward privacy [Bost et al. CCS'17] and propose alternative formulations. Our first construction $\Pi_\mathsf{BP}\text{-}\mathsf{prime}$ achieves a stronger notion of backward privacy whereas our next two constructions $\Pi_\mathsf{BP}$ and $\Pi_\mathsf{WBP}$ achieve optimal communication complexity at the cost of some additional leakage. The prototype implementations of our schemes depict the practicability of the proposed constructions and indicate that the cost of achieving backward privacy over forward privacy is substantially small.

Metadata
Available format(s)
PDF
Category
Cryptographic protocols
Publication info
Preprint. Minor revision.
Keywords
Dynamic Searchable Symmetric EncryptionBackward PrivacyForward Privacy
Contact author(s)
shaha @ iisc ac in
History
2019-05-08: received
Short URL
https://ia.cr/2019/446
License
Creative Commons Attribution
CC BY

BibTeX

@misc{cryptoeprint:2019/446,
      author = {Sanjit Chatterjee and Shravan Kumar Parshuram Puria and Akash Shah},
      title = {Backward Private DSSE: Alternative Formulations of Information Leakage and Efficient Constructions},
      howpublished = {Cryptology ePrint Archive, Paper 2019/446},
      year = {2019},
      note = {\url{https://eprint.iacr.org/2019/446}},
      url = {https://eprint.iacr.org/2019/446}
}
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