I am an assistant professor of computer science at Yale University and co-founder of Espresso Systems.

Previously, I was a PhD candidate at Stanford University, working with Dan Boneh in the applied cryptography research group.

The major theme of my research is privacy and verifiability in information systems, with a special attention on “blockchains” like Bitcoin and Ethereum. These systems have revolutionized trust, transparency, and privacy for applications in finance and beyond. As of January 2021, they collectively control assets worth over one trillion dollars.

Verifiability topics I work on include verifiable computation (how to efficiently verify that an untrusted service delivers the correct result of a computation), verifiable storage (how to verify an untrusted remote server is storing data properly), and verifiable fairness (how to verify that a public lottery selects a winner randomly without bias).

My recent work has largely focussed on the intersection of privacy and verifiability. The seemingly contradictory concept of an information system that is simultaneously private and publicly verifiable, enabled by zero-knowledge proofs, is a wonder of computer science. It has far-reaching applications, particularly within the realm of digital finance, where privacy is strongly needed but lack of transparency facilitates mismanagement and fraud.

My research draws from techniques in multiple areas of computer science, including cryptography, distributed systems, hardware architecture, and economics. Beyond topics in verifiability and zero-knowledge, my research has also spanned topics including secure computation, private database search (see Blind Seer), economics in cryptocurrencies (see Mining Pools) and applications of hardware trusted execution environments such as Intel SGX (see Iron).

Technology transfer is very important to me. My research on Verifiable Delay Functions (VDFs) sparked a multimillion dollar industry initiative (see VDF Alliance) and will play an important role in several blockchains including Ethereum 2.0, Chia, and Filecoin. My research on Proofs of Replication is the basis of Filecoin's incentive layer and consensus protocol. Filecoin is a live distributed storage system that already has reached a storage capacity exceeding 1.5 exabytes.

Twitter: @benafisch

Email: benafisch AT gmail

Pronouns: he/him