Paper 2024/1377

Security Strengthening of Threshold Symmetric Schemes

Ehsan Ebrahimi, University of Luxembourg
Abstract

In this paper, we study the security definitions of various threshold symmetric primitives. Namely, we analyze the security definitions for threshold pseudorandom functions, threshold message authentication codes and threshold symmetric encryption. In each case, we strengthen the existing security definition, and we present a scheme that satisfies our stronger notion of security. In particular, we propose indifferentiability definition and IND-CCA2 definition for a threshold pseudorandom function and a threshold symmetric encryption scheme, respectively. Moreover, we show that these definitions are achievable. Notably, we propose the first IND-CCA2 secure threshold symmetric encryption scheme.

Metadata
Available format(s)
PDF
Category
Secret-key cryptography
Publication info
Preprint.
Keywords
Threshold Pseudorandom FunctionThreshold Message Authentication CodeThreshold Symmetric Encryption
Contact author(s)
eebrahimi pqc @ gmail com
History
2024-09-04: approved
2024-09-02: received
See all versions
Short URL
https://ia.cr/2024/1377
License
Creative Commons Attribution
CC BY

BibTeX

@misc{cryptoeprint:2024/1377,
      author = {Ehsan Ebrahimi},
      title = {Security Strengthening of Threshold Symmetric Schemes},
      howpublished = {Cryptology {ePrint} Archive, Paper 2024/1377},
      year = {2024},
      url = {https://eprint.iacr.org/2024/1377}
}
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