Light Clients for Lazy Blockchains

Ertem Nusret Tas; David Tse; Lei Yang; Dionysis Zindros

Paper 2022/384

Light Clients for Lazy Blockchains

Ertem Nusret Tas

, Stanford University

David Tse

, Stanford University

Lei Yang

, Massachusetts Institute of Technology

Dionysis Zindros

, Stanford University

Abstract

Lazy blockchains decouple consensus from transaction verification and execution to increase throughput. Although they can contain invalid transactions (e.g., double spends) as a result, these can easily be filtered out by full nodes that check if there have been previous conflicting transactions. However, creating light (SPV) clients that do not see the whole transaction history becomes a challenge: A record of a transaction on the chain does not necessarily entail transaction confirmation. In this paper, we devise a protocol that enables the creation of efficient light clients for lazy blockchains. The number of interaction rounds and the communication complexity of our protocol are logarithmic in the blockchain execution time. Our construction is based on a bisection game that traverses the Merkle tree containing the ledger of all - valid or invalid - transactions. We prove that our proof system is succinct, complete and sound, and empirically demonstrate the feasibility of our scheme.

Note: Financial Cryptography and Data Security 2024 (FC24)

Metadata

Available format(s): PDF
Category: Cryptographic protocols
Publication info: Published elsewhere. Minor revision. Financial Cryptography and Data Security 2024 (FC24)
Keywords: blockchains lazy blockchains interactive verification games refereed computation
Contact author(s): nusret @ stanford edu
dntse @ stanford edu
leiy @ csail mit edu
dionyziz @ stanford edu
History: 2024-01-11: last of 3 revisions; 2022-03-28: received; See all versions
Short URL: https://ia.cr/2022/384
License: CC BY

BibTeX

@misc{cryptoeprint:2022/384,
      author = {Ertem Nusret Tas and David Tse and Lei Yang and Dionysis Zindros},
      title = {Light Clients for Lazy Blockchains},
      howpublished = {Cryptology ePrint Archive, Paper 2022/384},
      year = {2022},
      note = {\url{https://eprint.iacr.org/2022/384}},
      url = {https://eprint.iacr.org/2022/384}
}