2018年-数据局_区块链系列报告一_18页_170kb

Tezos: A Self-Amending Crypto-Ledger Summary

Core Content

Tezos is a self-amending blockchain protocol designed to address key limitations in existing cryptocurrencies, particularly Bitcoin. Unlike traditional blockchains that require hard forks for protocol upgrades, Tezos enables stakeholders to approve amendments through a formalized process, ensuring that changes are endogenous and secure. This approach aims to prevent the fragmentation and loss of network value that can occur with incompatible protocols.

Main Viewpoints

• Dynamic Innovation: Tezos allows for continuous and organic evolution of the protocol without the need for disruptive forks, which can lead to loss of value and network fragmentation.
• Proof-of-Stake (PoS): Tezos implements a PoS mechanism to avoid the centralization and inefficiency issues associated with proof-of-work (PoW).
• Formal Verification: The protocol is designed with correctness in mind, using OCaml as its implementation language due to its strong typing and formal verification capabilities.
• Modular Design: Tezos separates blockchain protocols into three distinct components: network, transaction, and consensus protocols, which can be independently upgraded and tested.

Key Information

1. Motivation

• Protocol Fork Problem: Bitcoin's inability to dynamically evolve without causing network splits.
• Centralization and Cost: PoW leads to mining pool concentration and high energy costs, which can undermine the decentralization and security of the system.
• Smart Contracts Limitation: Bitcoin's limited scripting capabilities restrict the development of complex smart contract systems.
• Correctness Concerns: The security of Bitcoin is compromised by the use of unverified code and languages like C++ that are prone to bugs and vulnerabilities.

2. Abstract Blockchains

• Three Protocols:
  • Network Protocol: Handles communication, peer discovery, and transaction broadcasting.
  • Transaction Protocol: Defines the rules for validating transactions and managing balances.
  • Consensus Protocol: Determines how blocks are validated and how rewards are distributed.
• Network Shell: A generic framework that isolates and integrates the transaction and consensus protocols, enabling flexibility and modularity.
• Protocol Functions:
  • apply: Transforms the current state (Context) using a block.
  • score: Determines the canonical branch of the blockchain.
  • set_test_protocol and promote_test_protocol: Allow for testing and deployment of new protocols in a controlled and secure manner.

3. Proof-of-Stake

• Avoiding 51% Attacks: PoS reduces the risk of attacks by making it more costly to control the network through stake rather than computational power.
• Incentive Alignment: Miners are stakeholders, thus incentivized to maintain low transaction costs and secure the network.
• Scalability and Security: As the currency appreciates, the cost of an attack increases, ensuring better security over time.

4. Potential Developments

• Privacy Enhancements: Tezos supports privacy-preserving transactions using techniques like ring signatures and zero-knowledge proofs.
• Amendment Rules: A constitution-like framework allows stakeholders to vote on protocol changes, promoting a democratic and transparent evolution process.
• Futarchy: A governance model where stakeholders can vote on outcomes rather than specific policies, enhancing decision-making efficiency.
• Collective Action Solutions: Tezos aims to reduce the risk of bad actors by using formal verification and structured governance, ensuring that the system is robust and self-sustaining.

Conclusion

Tezos represents a significant shift in blockchain design, offering a self-amending, modular, and formally verified alternative to traditional cryptocurrencies. By using a proof-of-stake mechanism and a stakeholder-driven amendment process, it seeks to enhance security, reduce centralization, and promote sustainable innovation in the crypto space. The choice of OCaml ensures a high level of correctness and reliability, making Tezos a promising candidate for the future of decentralized systems.