Nervos Common Knowledge Base (CKB); Protection-oriented, public, unauthorized “Asset Storage” is the blockchain of the Nchain chain and the Nervos network. In the context of blockchain, "common knowledge" refers to situations that are verified by global consensus, and a CKB is designed as a status verification system.

Nervos CKB generalizes Bitcoin's UTXO model to support user-defined tokens and smart contracts. It is designed to be adaptable, sustainable and flexible. CKB adapts to network conditions with a PoW algorithm that is adjusted according to the bandwidth of the participant nodes. It provides sustainability with the new token economy model that focuses on providing a long-term value store. Adaptive PoW algorithm also improves the sustainability of CKB and scales automatically with bandwidth improvements.

The combination of the CKB's generalized cell model and the RISC-V instruction set provides maximum flexibility: the cells can store the applicable code and reference other cells as links, allowing new algorithms to be easily integrated into CKB without a hard fork. CKB cells store the basics previously placed in private VMs. Updating key algorithms (eg Secp256k1) by keeping the VM as simple as possible and loading the program storage into cells; It is as simple as loading the algorithm in a new cell and updating the references.

Programming model: Generalized UTXO + RISC-V based VM

Nervos is a smart contract platform like Ethereum, but Nervos CKB is designed to be a status verification, storage system rather than a computing platform. Layer 1 verifies and stores blockchain states, and computation-intensive state generation takes place in Layer 2.

Nervos programming is based on cells inspired by Bitcoin's UTXO model. Cells contain random data such as status (such as user-defined token ownership) or business logic (such as code that validates token transfer). Cells are also immutable: they cannot be changed once they are created. Cells in the CKB can be considered as first-class citizens. Cells serve both as input and output of transactions and are the elements that make up the global state of the CKB.

Because cells can reference data to other cells as well as store their own data; the state and business logic of an asset decomposes. For example, the creator of a new token distributes the token's business logic (such as how many tokens it will be, whether new tokens can be created) into a cell, and then users control the cells that contain ownership and quantity data. Users' cells refer to the business logic cell, which contains a script that validates the new cell validity.

Owners of user-defined tokens (UDT) are real owners: they can only use cells that store token data. Stateful programs in the CKB do not combine the situation as in Ethereum smart contracts. Users own their cells.

Open commitments allow nodes to process transactions in parallel.

Blockchain evolution

Looking at previous public blockchains, one major challenge has been observed: once built, they remain stable. Although they are updated over time, their structure often remains the same. You can look at how difficult it is to bring Segwit to Bitcoin or Wasm to Ethereum to see the difficulty this brings.

While scripts in CKB are much more primitive than smart contracts in Ethereum, they offer a significant benefit - flexibility. Almost all algorithms and data structures are implemented in CKB scripts stored in the cell. If you are not satisfied with basic functions like signature algorithm or hash function, you can create whatever you want in CKB.

Nervos is produced from the word "nerve" and "cells" are specialized units that work together. Just as seen in the biological world. CKB cells can be customized to process information, transmit messages, or simply store information. Nervos CKB is more of an organic structure than traditional engineering studies. It allows the network to develop at the lowest level, taking advantage of the features that Charles Darwin observed years ago:

“Those who survive are the types that can adapt to the changing environment.”

Charles Darwin

Virtual machine

CKB VM, Using the RISC-V based command set to make smart contracts on Nervos CKB written in Rust allows scripts to be written in a wide variety of programming languages.

Consensus

Nervos uses PoW-based Nakamoto Consensus.

Token-economy

The local token CKB is designed to represent the right to use storage over time. The protocol restricts storage growth to monetary policy and collects "rent" from users through a "targeted inflation" program.

Project

The founders of Nervos are Jan Xie, Terry Tai, Kevin Wang, Daniel Lv and Cipher Wang: a team of core developers and researchers. The team's past projects include Ethereum customers (ruby-Ethereum and pyethereum), Spark Pool (2nd largest Ethereum mining pool), imToken (an Ethereum wallet with 7 million users) and CITA.

The team started Nervos studies in January 2018 and pre-sold some $ 28 million to some investors, including Sequoia and Polychain.