## 2 Related Works
(2022), on the other hand, proposed a blockchain-based data auditing scheme that aims at identifying malicious multi-cloud storage service providers and realizes batch verification of data stored by multiple cloud service providers through homomorphic verifiable tags. Compared to off-chain storage, on-chain storage employs a decentralized method where data is distributed across various nodes in the network ([PERSON] et al., 2020), with each node storing a portion of the data based on specific rules. On-chain storage is mainly categorized into two modes: collaborative storage mode and node-light mode. In the collaborative storage mode, multiple nodes work together to store and manage data: each node is tasked with holding a segment of the data and validating the data with other nodes. The main approaches to collaborative storage include techniques such as encoding, clustering, and sharding. In shard-based collaborative storage, data are divided into multiple small segments, known as shards, and dispersed across various nodes in the network. This approach aims to enhance storage efficiency and system scalability. [PERSON] et al. [24] developed a consortium blockchain framework called BETASCO, which focuses on the sharded processing of smart contracts. The system allocates an independent shard environment for each smart contract and employs distributed hash technology to locate contracts, ensuring that each transaction is accurately delivered to the corresponding smart contract shard. [PERSON] [25] conducted a study on a sharded consortium blockchain system named Meepo, which utilizes cross-timing and cross-calling techniques to improve operational efficiency across shards. In coding-based collaborative storage, data are partitioned and coded and then distributed and stored on multiple nodes of the network, which enhances the reliability and fault tolerance of the data. [PERSON] et al. [26] explored how to apply network coding techniques to P2P content distribution systems. [PERSON] et al. [27] developed a latency-aware coded data block allocation algorithm that specifically deals with the problem of selecting the number and location of coded data blocks to be stored. Cluster-based collaborative storage stores and manages data by forming clusters of multiple nodes. This approach enables nodes to share data storage and validation tasks together, which enhances the system's reliability and scalability [28]. [PERSON] et al. [29] developed a multi-node collaborative storage strategy called ICIStrategy, which divides all the participants into a number of clusters, and each cluster holds the network's copy of all the data in the network. Every node in the cluster does not need to maintain a full data duplicate, thereby decreasing the scale of data each node must store, relieving the storage pressure, and lowering the communication overhead within the clusters. [PERSON] et al. [30] designed a lightweight and scalable consensus protocol and distributed the data blocks in a balanced manner among the clusters through a parallel processing module. The nodes are tasked with verifying the blocks and communicating with the distributed consensus protocol through the Message Passing Interface (MPI) communicator to exchange consensus information with the distributed consensus manager and their respective coordinators. The validated data blocks will be stored in the node's local memory and other nodes to enhance the overall integrity and reliability of the data. The light node model allows light nodes to perform transaction verification without having to download data from the entire blockchain [31]. This is achieved by synchronizing only block header information and employing Simplified Payment Verification (SPV), which allows light nodes to confirm the validity of a transaction without the need for large amounts of storage space. [PERSON] et al. [32] designed a blockchain system consisting entirely of light nodes, where it is assumed that any two nodes are able to perform data transfer either directly or via broadcast.