第五十六期

报告人：Hongyin Chen, Technion

时间：4月16日（星期四）7:00pm

地点：静园五院204

Host：王颖  图灵班2019级

报告信息

Title

Prrr: Personal Random Rewards for Blockchain Reporting

Abstract

Smart contracts, the stateful programs running on blockchains, often rely on reports. Publishers are paid to publish these reports on the blockchain. Designing protocols that incentivize timely reporting is the prevalent reporting problem. But existing solutions face a security-performance trade-off: Relying on a small set of trusted publishers introduces centralization risks, while allowing open publication results in an excessive number of reports on the blockchain. We identify the root cause of this trade-off to be the standard symmetric reward design, which treats all reports equally. We prove that no symmetric-reward mechanism can overcome the trade-off.

We present Personal Random Rewards for Reporting (Prrr), a protocol that assigns random heterogeneous values to reports. We call this novel mechanism-design concept Ex-Ante Synthetic Asymmetry. To the best of our knowledge, Prrr is the first game-theoretic mechanism (in any context) that deliberately forms participant asymmetry. Prrr employs a second-price-style settlement to allocate rewards, ensuring incentive compatibility and achieving both security and efficiency. Following the protocol constitutes a Subgame-Perfect Nash Equilibrium, robust against collusion and Sybil attacks. Prrr is applicable to numerous smart contracts that rely on timely reports.

Biography

Hongyin Chen received his Ph.D. from Peking University advised by Prof. Xiaotie Deng. He is currently a postdoc in Ittay Eyal's group at the Technion. His work centers on mechanism design and game theory in blockchain.

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