Kaya Alpturer will present his General Exam "Optimal RANDAO Manipulation" on May 12, 2025 at 12:30pm in CS 301. Committee: Matt Weinberg (adviser), Mark Braverman, Pramod Viswanath All are welcome to attend the talk. Abstract: It is well-known that RANDAO manipulation is possible in Ethereum if an adversary controls the proposers assigned to the last slots in an epoch. We provide a methodology to compute, for any fraction α of stake owned by an adversary, the maximum fraction f(α) of rounds that a strategic adversary can propose. We further implement our methodology and compute f(⋅) for all α. For example, we conclude that an optimal strategic participant with 5% of the stake can propose a 5.048% fraction of rounds, 10% of the stake can propose a 10.19% fraction of rounds, and 20% of the stake can propose a 20.68% fraction of rounds. * Roughgarden, Tim. Twenty lectures on algorithmic game theory . Cambridge University Press, 2016. * Dwork, Cynthia, Nancy Lynch, and Larry Stockmeyer. "Consensus in the presence of partial synchrony." Journal of the ACM (JACM) 35.2 (1988): 288-323. * Fischer, Michael J., Nancy A. Lynch, and Michael S. Paterson. "Impossibility of distributed consensus with one faulty process." Journal of the ACM (JACM) 32.2 (1985): 374-382. * Yin, Maofan, et al. "HotStuff: BFT consensus with linearity and responsiveness." Proceedings of the 2019 ACM symposium on principles of distributed computing . 2019. * Cleve, Richard. "Limits on the security of coin flips when half the processors are faulty." Proceedings of the eighteenth annual ACM symposium on Theory of computing . 1986. * Eyal, Ittay, and Emin Gün Sirer. "Majority Is Not Enough: Bitcoin Mining Is Vulnerable." International Conference on Financial Cryptography and Data Security . Berlin, Heidelberg: Springer Berlin Heidelberg, 2014. * Sapirshtein, Ayelet, Yonatan Sompolinsky, and Aviv Zohar. "Optimal selfish mining strategies in bitcoin." Financial Cryptography and Data Security: 20th International Conference, FC 2016, Christ Church, Barbados, February 22–26, 2016, Revised Selected Papers 20 . Springer Berlin Heidelberg, 2017. * Cai, Yang, Nikhil R. Devanur, and S. Matthew Weinberg. "A duality based unified approach to bayesian mechanism design." Proceedings of the forty-eighth annual ACM symposium on Theory of Computing . 2016. * Beyhaghi, Hedyeh, and S. Matthew Weinberg. "Optimal (and benchmark-optimal) competition complexity for additive buyers over independent items." Proceedings of the 51st Annual ACM SIGACT Symposium on Theory of Computing . 2019. * Roughgarden, Tim. "Transaction Fee Mechanism Design." Journal of the ACM 71.4 (2024): 1-25. * Heilman, Ethan, et al. "Eclipse attacks on {Bitcoin’s}{peer-to-peer} network." 24th USENIX security symposium (USENIX security 15) . 2015. * Matheus V. X. Ferreira, S. Matthew Weinberg. “Proof-of-Stake Mining Games with Perfect Randomness” EC 2021.