Lavinia: An audit-payment protocol for censorship-resistant storage

Abstract

As distributed storage systems grow in popularity, there is now a demand for a reliable incentive and payment system to guarantee and reward the pristine storage of documents. However, many existing proof-of-retrieval and micropayment protocols are not secure in a censorship resistance setting, in which powerful adversaries may infiltrate a system or coerce the original publisher to remove content. Additionally, most existing censorship resistance systems lack a rigorous game-theoretic analysis. We propose Lavinia, an audit and payment protocol for censorship-resistant storage. Lavinia incentivizes document availability by providing micropayments to participating servers in exchange for honestly storing and serving content. Our protocol enables the implementation of a digital printing press as described in Anderson’s Eternity Service: allowing the publisher, as opposed to public interest or an appointed editorial board, to decide whether a document is worth storing, and for how long. In addition to proving the security of our protocol, we provide an in-depth game-theoretic analysis and show that self-interested participants of our system will faithfully implement the desired behaviour and continue to store documents until their expiration date.