Paper 2026/2129

Cryptanalysis of a Polynomial-Based Redactable Blockchain

Alexander Ushakov, Stevens Institute of Technology
Abstract

We analyze a recently published construction of redactable blockchains based on multivariate polynomial equations. We show that its public integrity conditions reveal sufficient algebraic structure to recover the relevant private evaluation points efficiently. As a consequence, the blockchain unauthorized redaction problem reduces to univariate root finding over a finite field followed by solving a linear system. We also discuss an alternative attack based on linearization.

Metadata
Available format(s)
PDF
Category
Attacks and cryptanalysis
Publication info
Preprint.
Keywords
Redactable blockchainsmultivariate polynomial equationscryptanalysisalgebraic attacks
Contact author(s)
aushakov @ stevens edu
History
2026-09-22: approved
2026-09-20: received
See all versions
Short URL
https://ia.cr/2026/2129
License
Creative Commons Attribution
CC BY

BibTeX

@misc{cryptoeprint:2026/2129,
      author = {Alexander Ushakov},
      title = {Cryptanalysis of a Polynomial-Based Redactable Blockchain},
      howpublished = {Cryptology {ePrint} Archive, Paper 2026/2129},
      year = {2026},
      url = {https://eprint.iacr.org/2026/2129}
}
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