Back to Events

Grassroot Consensus: Foundations for Democratic Distributed Ledger Technology

[Seminar Series Spring ’23] | [Onsite | Brown-Bag]


Today, the digital realm is dominated by two architectures: Autocratic digital platforms (e.g., Facebook, Twitter, Amazon marketplace, Uber, Airbnb) and plutocratic cryptocurrencies (e.g., Bitcoin, Ethereum), creating perhaps the greatest inequality of power and wealth in modern history. In this talk we will present our work towards a third alternative: An architecture that is grassroots and can in principle support egalitarian and democratic alternatives to digital platforms and to mainstream cryptocurrencies.

The core of the architecture is a grassroots consensus protocol stack, designed for serverless peer-to-peer execution by personal devices, i.e., smartphones. The protocol stack incorporates: (1) Grassroots dissemination, in which dissemination occurs only among friends, and only of blocks by persons both friends follow. It is powerful enough to support Twitter-like and WhatsApp-like serverless social networking. (2) Leader-based equivocation exclusion, sufficient to realize sovereign cryptocurrencies, which can support the grassroots formation of digital economies without external capital or credit. (3) Grassroots consensus, an alternative to permissioned and permissionless consensus protocols in which extant participants determine whether and how to admit new participants according to the protocol’s constitution. The key envisioned application of grassroots consensus is grassroots social contracts serving democratic Decentralized Autonomous Organizations (DAOs). Grassroots social contracts, unlike smart contracts and DAOs, are executed by their participants, not by third-party miners, and thus provide grassroots foundations for democratic DAOs that are sovereign and truly autonomous.

The protocol stack employs the blocklace – a DAG-like partially-ordered generalization of the totally-ordered blockchain. The construction so far has been mathematical. We will discuss plans for its implementation.


Prof. Dr Ehud Shapiro

Ehud Shapiro is a multidisciplinary scientist, entrepreneur, artist, and political activist. He earned his BA/BSc in mathematics and philosophy from Tel Aviv University in 1979 and his PhD in computer science from Yale in 1982; he has been with the Weizmann Institute of Science since then, where he holds the Harry Weinrebe Professorial Chair of Computer Science and Biology. His PhD research on inductive logic programming and algorithmic debugging has served as a foundation for these two disciplines. At Weizmann, he developed the discipline of concurrent logic programming and the distributed logic programming language Concurrent Prolog, in collaboration with the Japanese Fifth Generation Computer Systems project. In 1993, he founded Ubique Ltd., the first internet social networking software start-up. In 1995, Ubique launched Virtual Places 1.0, a social networking/2D metaverse application with 2D avatars on web pages, providing instant messaging, chat rooms, joint and guided web surfing, online events and games, and integrated voice-over IP. This was well before Facebook was founded and two and a half decades before its interest in the metaverse. He sold Ubique to America Online, performed a management buyout, and then sold it again in 1998 to IBM, where its technology was the basis of Sametime, IBM’s successful corporate network communication and collaboration product.

Upon return to Weizmann in 1998, Ehud switched to biology, and led research projects on biomolecular computers, synthetic biology, and human cell lineage reconstruction, for which he received two ERC Advanced Grants. In 2017, he began working on digital democracy, initially with Nimrod Talmon and later also with collaborators and a research team he formed at Weizmann. In 2020, Ehud founded a new Israeli political party, democratit. Ehud is a bass singer and the founder and artistic director of the Ba Rock Band.