Blockchains that support a general contract layer (e.g., Ethereum) export the functionality of a general-purpose, ownerless, and open-access computer that can enforce property rights for digital data.  How is such functionality implemented?  Using a lot of extremely cool computer science ideas! And like everywhere else in computer science, theory plays an undeniable role in the understanding and advancement of this technology.  In this talk, Tim Roughgarden will highlight three examples (among many):

• Possibility and impossibility results for permissionless consensus (i.e., implementing an “ownerless” computer).
• Incentive-compatible transaction fee mechanism design (part of implementing an “open-access” computer).
• Succinct proofs of computation (for boosting the computer’s power by piggybacking on off-chain computation).

Parts of this talk are based on joint work with Andrew Lewis-Pye.