Welcome to CESS, the first decentralized cloud storage network that supports enterprise-level commercial applications! Cumulus Encrypted Storage System is a full-stack solution developed with Substrate, dedicated to building a high-speed, secure, and scalable decentralized cloud storage network for Web3. As an open-source public blockchain network, CESS not only offers decentralized data storage services, it also serves users and creators as a platform for on-chain data sharing, as well as developing and deploying DAPPs. CESS will implement multiple mechanisms and proof schemes, including Proof of Data Reduplication and Recovery (PoDR2), to ensure data privacy and availability. Also, a unique Multi-format Data Rights Confirmation Mechanism (MDRC) and a high-order data encryption technology will be implemented to achieve the data owner rights confirmation and copyright protection. Data lineage can be tracked and visualized in the blockchain browser. To be compatible with other existing blockchain applications, the CESS virtual machine is EVM/WASM compatible, providing a more convenient, secure, and efficient platform for DAPP development. In addition, CESS designs an advanced distributed file storage system to efficiently manage the network storage resources. The CESS API supports two types of data storage: object storage and block storage.