Scalable System for Indexing and Providing Access to Verifiable Blockchain Transaction Data

Abstract

Technological advancements in blockchain solutions have allowed for the development of applications that were not previously viable. Many of those applications will require querying potentially vast amounts of transaction data. With a potential transaction throughput orders of magnitude higher than was possible until recently, such applications would benefit from delegating those queries to third party services with the computing power and infrastructures allowing the quick return of accurate results. The problem, however, with delegating queries, is that it creates a need for trust in a third party that blockchain technology was explicitly designed to eliminate. Such a third party query service should then be able to provide proof of the authenticity of the results it returns to its users. In this project, we build an API that provides fast and scalable random access to transaction data on the Algorand blockchain and allows queries according to a number of transaction parameters. A mathematical proof based on the principle of Zero-Knowledge Proof allows the user of the API to verify the authenticity and completeness of the queried transaction data. This work is based on the vChain framework described in the paper "vChain: Enabling Verifiable Boolean Range Queries over Blockchain Databases" by Cheng Xu, Ce Zhang, and Jianliang Xu.