Abstract. This talk will explore the design of Arbitrum, a leading optimistic rollup on Ethereum, focusing on the threat model and security assumptions, protocol design approach, mechanisms, and basic chain economics. The talk will conclude by discussing future challenges and potential research directions for advancing L2 and L3 systems.

Abstract. In this keynote we will explore the critical challenges of privacy and governance in the context of public blockchains and Decentralized Finance (DeFi). Drawing on theoretical and empirical insights from recent research projects, the talk delves into the nuanced dynamics between privacy preservation and governance mechanisms, highlighting their implications for stakeholder trust, regulatory compliance, and the sustainable growth of DeFi ecosystems. This discussion aims to foster an interdisciplinary dialogue among academics from various fields, practitioners, and policymakers, fostering innovative solutions to overcome these challenges and create a neutral infrastructure for a digital economy.