Paper 2020/1039
Moderated Redactable Blockchains: A Definitional Framework with an Efficient Construct
Mohammad Sadeq Dousti and Alptekin Küpçü
Abstract
Blockchain is a multiparty protocol to reach agreement on the order of events, and to record them consistently and immutably without centralized trust. In some cases, however, the blockchain can benefit from some controlled mutability. Examples include removing private information or unlawful content, and correcting protocol vulnerabilities which would otherwise require a hard fork. Two approaches to control the mutability are: moderation, where one or more designated administrators can use their private keys to approve a redaction, and voting, where miners can vote to endorse a suggested redaction. In this paper, we first present several attacks against existing redactable blockchain solutions. Next, we provide a definitional framework for moderated redactable blockchains. Finally, we propose a provable and efficient construct, which applies a single digital signature per redaction, achieving a much simpler and secure result compared to the prior art in the moderated setting.
Note: In DPM 2020, CBT 2020: Data Privacy Management, Cryptocurrencies and Blockchain Technology, pp 355-373. https://doi.org/10.1007/978-3-030-66172-4_23
Metadata
- Available format(s)
-
PDF
- Category
- Foundations
- Publication info
- Published elsewhere. Minor revision. DPM 2020, CBT 2020: Data Privacy Management, Cryptocurrencies and Blockchain Technology
- DOI
- 10.1007/978-3-030-66172-4_23
- Keywords
- BlockchainBitcoinModerated Redactable BlockchainFormal Threat ModelSignature Scheme
- Contact author(s)
- msdousti @ gmail com
- History
- 2021-01-19: revised
- 2020-08-28: received
- See all versions
- Short URL
- https://ia.cr/2020/1039
- License
-
CC BY
BibTeX
@misc{cryptoeprint:2020/1039,
author = {Mohammad Sadeq Dousti and Alptekin Küpçü},
title = {Moderated Redactable Blockchains: A Definitional Framework with an Efficient Construct},
howpublished = {Cryptology {ePrint} Archive, Paper 2020/1039},
year = {2020},
doi = {10.1007/978-3-030-66172-4_23},
url = {https://eprint.iacr.org/2020/1039}
}
