Proof protocols ­­­­­­— probabilistically checkable proofs, interactive proofs, and zero-knowledge proofs — have seen exciting advances in recent years, from theoretical aspects all the way to deployment. At the same time, blockchain technology — enabled by techniques from decentralized consensus protocols, cryptography, and game theory — not only is challenging centralized financial control in the context of real­-world systems like Bitcoin and Ethereum but also has the potential to be a foundation for real­-world distributed systems used for public benefit.

These two strands, proof protocols and blockchain technology, are intertwined. On the one hand, proofs can enhance the auditability and accountability of decentralized systems while preserving user privacy; for this reason, proofs are a key ingredient in the future growth and evolution of blockchains. On the other hand, decentralized consensus protocols could themselves be used to design improved proof protocols and other cryptographic primitives.

The stability and success thus far of blockchain­-based systems raise pressing questions in distributed algorithms, cryptography, and game theory. Such decentralized public systems also raise economic, legal, and ethical questions whose study is intimately tied to the underlying technology and its trajectory.

This program brought together researchers from computer science and beyond whose research is contributing to three subthemes: proof systems, decentralized consensus, and applications of these to society, economics, and cryptocurrencies.

This program was supported in part by the Institute for Business & Social Impact.