Nervos is a network of scaleable and interoperable blockchains built on top of an open network - which we call the Common Knowledge Base (CKB). CKB is built as a security anchor for all blockchains (and layer 2 protocols such as state channels) in the Nervos network. It enables enterprises and application developers to decide what goes into the blockchain.
Nervos is a network of interoperable protocols instead of a single blockchain, as commonly in other platforms. The public blockchain (the Nervos CKB) is just one of many components of the network and plays a limited role to provide decentralization and security. The entire Nervos Network together serves as the platform for dApps and protocols.
The overall design of Nervos aims to use a layered approach to balance the different tradeoffs of a decentralized system. The Nervos CKB is a public chain designed to provide the most data abstraction power, broadest consensus, and strongest security, without sacrificing decentralization. The Nervos AppChains are optimized for expressiveness, performance, finality and throughput. By separating those concerns, we're able to design specific economics models for each layer to best optimize for their roles in the system. The more modular and specialized design also allows Nervos to evolve quicker than monolithic systems.
There are quite a few upcoming projects that focus on more efficient consensus algorithms to achieve higher transaction per second (TPS). Consensus algorithms are of critical importance to decentralized systems. However, many consensus algorithms either sacrifice openness of the decentralized system to achieve throughput, or are very experimental and need to be proven in production. The approach that Nervos takes for scalability is through core architectural design. Nervos separates decentralized knowledge and computation, to push the heavy lifting off the main public blockchain. The public blockchain can focus on the common knowledge that needs global consensus and provide security to Nervos AppChains.
The algorithm is a hybrid consensus that combines the best of traditional Byzantine Fault Tolerance (BFT) and Nakamoto Consensus to give high performance in normal situations and availability when the network partitions. Traditional BFT consensus algorithms can achieve throughput and transaction confirmation speed on par with centralized systems. However, it is difficult for nodes to join or exit freely, and the network's performance decreases rapidly with the increasing number of consensus participating nodes. Traditional BFT consensus algorithms have lower tolerance on network faults. When the network partitions, nodes cannot achieve consensus and the network loses liveliness, making it difficult to meet the availability requirements of permissionless blockchains. The Nakamoto Consensus, popularized by Bitcoin’s Proof of Work, has excellent openness and availability. Nodes in the Bitcoin network may join and exit freely with minimal cost, and the network performance remains constant with more participating nodes. However, its throughput is quite low. In Nervos, the team has combined Nakamoto Consensus and traditional BFT consensus algorithms in a secure way to arrive at a new hybrid consensus algorithm that gives the optimal balance in consistency, availability, fairness, and operational cost.
The Nervos native tokens are used to bond with storage units to store common knowledge in the blockchain. Users pay the storage cost with the token's liquidity, so the cost scales to both space (the size of the knowledge that needs to be saved) and time (the duration that the knowledge needs to be saved) and is better aligned with the ongoing preservation cost of knowledge.
For protocol developers, the Nervos CKB offers a versatile settlement engine with features such as built-in cryptographic primitives and "just enough" support for validations. It will be more expressive and efficient as a validation/settlement engine and less likely to introduce bugs than a general purpose Ethereum smart contract platform.
Engineering started in January 2018. We will release the Nervos appchain by Q3 2018, along with a blockchain browser Microscope and dApp wallet Neuron. Our testnet is estimated to be ready in Q4 2018 and mainnet in Q2 2019.
Developers can use any language they would like to create applications on Nervos.