A Basic Framework of BlockchainBased Decentralized Verifiable Outsourcing With the development and application of blockchain technology, more and more fields are beginning to use blockchains for industrial innovation, In recent years. At the same time, the data integrity verification techniques based on blockchain have also attracted wide attention of researchers. However, the stateoftheart schemes are only using the structure of the blockchain on centralized server which cannot leverage the characteristics of the blockchain and resist malicious modification attacks. In addition, the centralized blockchain structure introduces additional storage and computing costs. In this paper, we propose a decentralized verifiable outsourcing framework based on blockchain networks, in which no administrators are required to be in charge of auditing and recording data changes.

A New Structure of Blockchain to Simplify the Verification. Blockchain is first introduced in Bitcoin and has good performance in cryptocurrencies. With the growth of chain, the height of blockchain in Bitcoin has reached five hundred thousand, and the entire capacity of chain is more than 500 GB. If a light node wants to verify a transaction, it has to spend nearly one week to download the data of whole chain with download rate of 1 MBs, which seriously hinders the usage of blockchain. In order to resolve this problem, checkpoint is used to reduce the capacity of data, but this centralized scheme obviously violates the decentralization of blockchain. Other schemes are proposed will change the structure of blockchain may suffer the risk that adversary can fork a blockchain to cheat the light nodes. In this paper, we propose a novel blockchain architecture, which simplifies the verification in blockchain and is compatible with most consensus mechanism. We append backlinks in some blocks, such that blocks not only look like a chain but also like a binary tree. We also introduce a challenge mechanism for against the forking attack on light nodes.