In this paper, we present a generic design of redactable blockchain protocol in the permissionless setting, applied to both proof-of-stake and proof-of-work blockchain. Our protocol can (1) maintain the same adversary bound requirement as the underlying blockchain, (2) support various network environments, (3) offer public verifiability for any redaction, and (4) achieve instant redaction, even only within one slot in the best case, which is desirable for redacting harmful data. Furthermore, we define the first ideal functionality of redactable blockchain and conduct security analysis following the language of universal composition. Finally, we develop a proof-of-concept implementation showing that the overhead remains minimal for both online and re-spawning nodes, which demonstrates the high efficiency of our design.
Category / Keywords: applications / Blockchain; Proof-of-Stake; Proof-of-Work; Redactable Blockchain Date: received 27 Feb 2021, last revised 23 Nov 2021 Contact author: xinyuli1920 at gmail com, xujing at iscas ac cn, lingyuan2018 at iscas ac cn, luyuan at iscas ac cn, qiang tang at sydney edu au, zhenfeng at iscas ac cn Available format(s): PDF | BibTeX Citation Version: 20211123:105903 (All versions of this report) Short URL: ia.cr/2021/223