Privacy-Preserving Petitions on Public Blockchains

Online petitions are commonly created and signed on few central platforms that retain control over content, participation, and technical implementation. To improve confidence in online petitions and thus increase their impact, we propose to leverage blockchain technology to store and process petitions. We present a prototype of a petition platform, that implements schemes designed to protect the signers’ identities while maintaining the guarantee that each participant can sign only once. We evaluate their privacy properties, performance and deployment costs on Ethereum and Optimism.