Shellproof: More Efficient Zero-Knowledge Proofs for Confidential Transactions in Blockchain

Abstract

Blockchain-based cryptocurrencies enable decentralization in transaction systems. The transaction details of traditional cryptocurrencies, e.g. Bitcoin, are public to everyone, which can be a problem in confidential scenarios. To deal with the confidential problem, some current cryptocurrencies adopt confidential transactions to hide the details in proofs. Among all confidential transaction implementations, Bulletproof is the most efficient approach without a trusted setup. In this paper, we analyze Bulletproof's design and show that the computation cost can be further reduced. Based on our analysis, we propose Shellproof, which is only half of the computation cost of Bulletproof. Experimental results show Shellproof can preserve the advantages of Bulletproof and is much more efficient than Bulletproof.