6533b835fe1ef96bd129fd7c

RESEARCH PRODUCT

Moderated Redactable Blockchains: A Definitional Framework with an Efficient Construct

Alptekin KüpçüMohammad Sadeq Dousti

subject

020203 distributed computingComputer sciencemedia_common.quotation_subject02 engineering and technologyConstruct (python library)RedactionComputer securitycomputer.software_genreDigital signatureOrder (exchange)020204 information systemsVoting0202 electrical engineering electronic engineering information engineeringFork (file system)Protocol (object-oriented programming)computerPrivate information retrievalmedia_common

description

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.

https://doi.org/10.1007/978-3-030-66172-4_23