Nervos Network RFCs

CKB utilizes two primary serialization formats depending on the use case:

1. Molecule: A canonicalization and zero-copy serialization format used for core CKB operations. It is optimized for performance and deterministic encoding.
2. JSON: Used specifically for node RPC services via the JSON-RPC specification.

The CKB P2P Networking layer utilizes a scoring system to mitigate network security threats, specifically targeting 'Eclipse Attacks'. In an Eclipse Attack, a malicious actor attempts to occupy all of a victim node's peer connection slots to filter the victim's view of the blockchain.

To defend against this, CKB clients are expected to implement a scoring system based on three core principles:

1. Peer Information Storage: Nodes should store as much peer information as possible.
2. Continuous Scoring: Nodes must continuously score peers based on both good and bad behaviors.
3. Peer Management: Nodes should prioritize retaining high-score (good) peers and evicting low-score (bad) peers.

This scoring system provides a foundation for implementing more sophisticated security strategies similar to those used in the Bitcoin network to handle generalized network security cases.

The CKB Light Client Protocol is a FlyClient-based implementation designed to allow resource-constrained clients to verify the validity of the CKB blockchain without downloading all blocks or headers.

Key features include:

• Efficiency: It requires downloading only a logarithmic number of block headers.
• Low Storage: It only needs to store a single block header between executions.
• Security: It uses a sampling protocol tailored for the [NC-Max] difficulty adjustment algorithm to ensure security against adversaries with significant computing power.

CKB uses an improved Nakamoto consensus based on Proof-of-Work (PoW). It is designed to be an open, permissionless system where nodes can join or exit freely.

Key characteristics include:

• ASIC-neutral PoW: Uses a function designed to distribute tokens evenly and maximize network security by remaining resistant to specialized ASIC hardware.
• Node Roles: Nodes participate by either mining (running the algorithm to produce new blocks) or verifying (checking that new blocks are valid).
• Correctness Goals: Aims for eventual consistency (identical state across nodes), availability (timely responses), and fairness (equitable returns for miners).
• Performance Metrics: Performance is measured by transaction latency (time to confirmation) and transaction throughput (transactions per second), both of which are influenced by the block time.

The CKB P2P network layer implements a scoring system designed to mitigate security threats like 'Eclipse Attacks'. In an Eclipse Attack, malicious nodes attempt to occupy all of a victim node's peer connections to control the victim's view of the network, potentially leading to double-spending or manipulated hash power.

To defend against these attacks, the CKB P2P network follows three core rules:

1. Store Peer Information: Nodes should store as much information about known peers as possible.
2. Continuous Scoring: Nodes must constantly score peers based on their good and bad behaviors.
3. Peer Management: Nodes should retain high-scoring (good) peers and evict low-scoring (bad) peers.

CKB-VM version 2 is the specification implemented in the CKB Meepo hardfork. It is designed to improve the security, portability, and efficiency of scripts on the Nervos Network compared to version 1.

Key improvements include:

• Enhanced Script Isolation: Introduces the Spawn system call, allowing scripts to create child scripts with independent memory areas. This provides a secure alternative to dynamic library calls (which share memory space and pose security risks) and the Exec system call (which is difficult to use effectively).
• Performance Optimizations: Implements Macro-Operation Fusion (MOP) to reduce cycle counts for common instruction sequences, specifically targeting complex scripts like zero-knowledge proofs.