Blockchain is a new approach to create a distributed network which was first introduced in 2008. By the help of this disruptive technology a peer-to-peer network can be formed where nodes have to reach a consensus and form a chain from accepted blocks, while no central party or trusted controller is required. Among all the existing uses of this technology, decentralized storage systems are one of its prominent applications. Decentralized storage networks, are consisted of a group of people willing to rent out their unused hardware storage space. By implementing end-to-end encryption clients can securely transmit their files through a fully decentralized network and eliminate the risk of data failures that arise from centralized controls. In this network, storage providers are required to prove that they store unaltered files during the time. Also a smart contract between two parties is set out in which rental duration and cost that the customer needs to pay for using that storage space is clarified. This paper presents a comprehensive survey on the blockchain-based storage systems and how they work and then compares them with cloud-based storage networks. Also different techniques of consensus protocols in each group are explored. Next, we have an overview on the advantages and also weak points of blockchain-based storage systems. Finally, we discuss about future research directions.

区块链是一种创建分布式网络的新方法，该方法于2008年首次引入。借助这种破坏性技术，可以形成对等网络，其中节点必须达成共识并从公认的块中形成链，而没有需要中央方或受信任的控制器。在该技术的所有现有用途中，分散存储系统是其突出的应用之一。分散存储网络由一群愿意出租未使用的硬件存储空间的人组成。通过实施端到端加密，客户端可以通过完全分散的网络安全地传输其文件，并消除了由集中控制引起的数据故障的风险。在该网络中，要求存储提供商证明他们在这段时间内存储了未更改的文件。还规定了两方之间的智能合约，其中明确了客户使用该存储空间所需的租赁期限和成本。本文对基于区块链的存储系统及其工作方式进行了全面的调查，然后将其与基于云的存储网络进行了比较。还探讨了每组中不同的共识协议技术。接下来，我们对基于区块链的存储系统的优点和缺点进行概述。最后，我们讨论未来的研究方向。还探讨了各组中共识协议的不同技术。接下来，我们对基于区块链的存储系统的优点和缺点进行概述。最后，我们讨论未来的研究方向。还探讨了各组中共识协议的不同技术。接下来，我们对基于区块链的存储系统的优点和缺点进行概述。最后，我们讨论未来的研究方向。