Index Multilinear Tree-based Cross Chain for Decentralized Identity Governance

Decentralized identity has become an integral part of digital development. However, while ensuring privacy protection in distributed digital identity, achieving limited cost storage and retrieval of identity information remains a complex issue. Distributed storage often comes with significant costs and hinders rapid data retrieval. In this paper, we propose the use of index multilinear trees for data storage to enable fast identity information retrieval. Furthermore, based on the sidechain method in blockchain cross-chain technology, we propose storing the root hash of the index multilinear tree on the sidechain, offering a low-cost interoperability solution for complete information stored on the sidechain. We analyze the cost of this solution and conduct experimental performance testing to demonstrate its efficiency.