Paper 2021/657

Locally Reconstructable Non-malleable Secret Sharing

Bhavana Kanukurthi, Sai Lakshmi Bhavana Obbattu, Sruthi Sekar, and Jenit Tomy

Abstract

Non-malleable secret sharing (NMSS) schemes, introduced by Goyal and Kumar (STOC 2018), ensure that a secret can be distributed into shares (for some ), such that any (a parameter ) shares can be reconstructed to recover the secret , any shares doesn't leak information about and even if the shares that are used for reconstruction are tampered, it is guaranteed that the reconstruction of these tampered shares will either result in the original or something independent of . Since their introduction, non-malleable secret sharing schemes sparked a very impressive line of research. In this work, we introduce a feature of local reconstructability in NMSS, which allows reconstruction of any portion of a secret by reading just a few locations of the shares. This is a useful feature, especially when the secret is long or when the shares are stored in a distributed manner on a communication network. In this work, we give a compiler that takes in any non-malleable secret sharing scheme and compiles it into a locally reconstructable non-malleable secret sharing scheme. To secret share a message consisting of blocks of length each, our scheme would only require reading bits (in addition to a few more bits, whose quantity is independent of and ) from each party's share (of a reconstruction set) to locally reconstruct a single block of the message. We show an application of our locally reconstructable non-malleable secret sharing scheme to a computational non-malleable secure message transmission scheme in the pre-processing model, with an improved communication complexity, when transmitting multiple messages.

Metadata
Available format(s)
PDF
Category
Foundations
Publication info
Published elsewhere. Information Theoretic Cryptography (ITC) 2021
Keywords
non-malleabilitylocalitysecret-sharinginformation-theoretic cryptography
Contact author(s)
bhavana @ iisc ac in
oslbhavana @ gmail com
sruthi sekar1 @ gmail com
jenittomy @ gmail com
History
2021-05-20: received
Short URL
https://ia.cr/2021/657
License
Creative Commons Attribution
CC BY

BibTeX

@misc{cryptoeprint:2021/657,
      author = {Bhavana Kanukurthi and Sai Lakshmi Bhavana Obbattu and Sruthi Sekar and Jenit Tomy},
      title = {Locally Reconstructable Non-malleable Secret Sharing},
      howpublished = {Cryptology {ePrint} Archive, Paper 2021/657},
      year = {2021},
      url = {https://eprint.iacr.org/2021/657}
}
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