From Distributed Cryptography to Blockchain and Back

Secure distributed computation has long been a common “playground” for cryptography and distributed computing/systems research. Despite novel ideas flowing in both directions and central questions such as resilience to misbehavior and efficiency being treated by both communities, the difference in focus and the aimed properties have resulted in distinct approaches and considerable gaps in terminology, models, definitions and overall language. This mismatch is ever more present in emerging technologies such as blockchain and decentralized ledgers (DLT). The project’s novelties are: (1) a common blockchain-focused language for cryptography and distributed computing and translations of results to this common language; and (2) the study of feasibility, scalability, and efficiency of both classical distributed-cryptography primitives and blockchain-inspired ones, in models that better capture the challenges and idiosyncrasies of the latter. The project’s impacts are to forment collaborations that will ensure a holistic approach to the modern challenges posed by the above emerging technologies thus avoiding pitfalls that can hinder these technologies’ potential. The study of cryptographic hardness and decentralized trust assumptions can lead to a more flexible yet realistic and secure cyberspace. This project will actively promote an interdisciplinary research agenda focused on these technologies at Purdue, Texas A&M, and Northeastern, and will actively pursue inclusion to computer science research of underrepresented groups in the field.

Funded by the National Science Foundation, this project aims to address the above challenges by (1) creating a framework suitable for expressing foundational and modern questions from both cryptography and distributed computing, without ignoring privacy or computational considerations, a paradigm that is termed distributed cryptography, and theoretical transformations (“compilers”) for importing classical results into this framework, and further extending them under the cryptographic lens; (2) investigating feasibility, scalability, and efficiency of distributed cryptography primitives, such as secure multi-party computation, in models of execution and under assumptions inspired by DLT protocols; and (3) investigate how the paradigm of relying on a sparse resource, which is central in the blockchain literature (e.g., hashing power in proofs of work- and stake in proofs of stake-based protocols) can generically reshape distributed cryptography and allow us to circumvent long-standing impossibility results.