Preamble
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ZenIP: 42406
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Title: Technical Roadmap for the Migration of $ZEN and EON
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Owner: Zain Cheng
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Discussions-To: zain@horizenlabs.io
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Status: Draft
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Type: Technical
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Created: June 6, 2024
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License: MIT
Abstract
This proposal details the strategic technical plan for transitioning the $ZEN cryptocurrency from the current Horizen Mainchain and Horizen EON EVM to an advanced blockchain architecture, EON 2.0. The initiative seeks community approval for this migration, which aims to improve blockchain performance, incorporate the latest advancements in zero-knowledge proof systems, and enhance the utility of $ZEN.
Please note that this is a technical ZenIP, laying out the technical roadmap for the migration mechanics for $ZEN and EON. Tokenomics are not in scope for this ZenIP. Topics such as allocations and emissions are explicitly excluded, since they will be covered in greater detail in a separate proposal. Regardless of the circumstances, the max supply of 21 million $ZEN is sacrosanct and will remain untouched.
Motivation
Horizen ($ZEN) and EON are currently built on older technology stacks. The Horizen Mainchain is a fork of the Bitcoin C++ codebase with a block time of 2.5 minutes, while EON is written in Scala based on the Scorex SDK with an 18-second block time. To address the limitations of these legacy systems and align with the vision of Horizen as a home for ZK and an enduring utility for $ZEN, we propose migrating to EON 2.0.
EON 2.0 will be a fully compatible EVM, allowing DApp developers to develop and deploy Solidity smart contracts. Under the hood, EON’s EVM itself will be built on Substrate, allowing it to tightly integrate with zkVerify (which is also built on Substrate). This integration will enable direct access to zkVerify’s optimized proof verification pallets, which will provide zk app developers with seamless access to new proving systems and more cost efficient proof verification, thus enhancing the overall utility of zk applications within the Horizen ecosystem.
Rust also plays a pivotal role in this ecosystem, particularly given its reputation as the language of choice for cryptography and secure software development. The Substrate framework, written in Rust, benefits from the language’s robust memory safety features and performance efficiency, which are critical for implementing secure and fast cryptographic operations. Additionally, developers can use Rust to create custom pre-compiled contracts to extend EVM functionality and bridge operations to Substrate-based pallets.
Horizen’s migration to EON 2.0 is crucial for advancing the ecosystem, and this proposal will reassure the community that there is a robust and forward-looking plan in place to enhance the functionality, security, and scalability of the Horizen ecosystem.
Specification
The specification section breaks down the technical aspects of EON 2.0, detailing how each component will function to create a robust and efficient blockchain environment.
Figure 1: EON 2.0 as a fully compatible EVM, optimized for zk applications and built with Substrate framework (written in Rust).
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Consensus
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Mechanism: Delegated Proof of Stake (DPoS).
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Target Block Time: 6 seconds.
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Incentives
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Staking Rewards: Continuation of previous EON 1.0 staking mechanisms.
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Coinbase Rewards: Emissions-based rewards for producing blocks.
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Transaction Fees: Percentage of transaction fees go to block producers.
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$ZEN Emission
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The technological framework of EON 2.0 is designed to accommodate any emissions schedule for $ZEN, ensuring flexibility to maintain or adjust the current emissions rate as needed. This robustness underscores that emissions schedules are not a technical limitation.
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It is important to stress that this ZenIP does not discuss tokenomics, emissions, or allocations, which are reserved for a separate, dedicated ZenIP. In all scenarios, we acknowledge that the max supply of 21 million $ZEN is sacred and will be strictly preserved.
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Staking
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Continuing the approach of EON 1.0, EON 2.0 will also adopt a delegated proof-of-stake model, offering users the option to delegate $ZEN to nodes.
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Through this delegation, users can participate in the network and receive rewards proportional to their staked amounts.
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Snapshot-Based Migration
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State snapshots of both EON 1.0 and Horizen will be taken to ensure a seamless transition to EON 2.0.
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More information is detailed below in the Migration Path section.
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Core Technology & Execution Environment
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EON 2.0 is a fully compatible EVM, ensuring that developers can seamlessly deploy existing Solidity smart contracts on EON 2.0 without requiring any modifications.
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EON 2.0 integrates tightly with the zkVerify protocol, ensuring fast and cost-efficient verification of zk proofs.
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zkVerify (built using the Substrate framework and written in Rust) will operate as its own Relay Chain. To achieve this close integration, EON 2.0 will also utilize the Substrate framework as a parachain to zkVerify.
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It’s important to emphasize that while EON 2.0 uses the Substrate framework, it is entirely independent of the Polkadot ecosystem.
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EON forgers will be known as EON collators to reflect their role in producing blocks within the parachain structure.
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Migration Path
Figure 2: High-level steps for $ZEN & EON 2.0 migration, including the prolonged claim window for $ZEN from the Mainchain. $ZEN in EON 1.0 will not require any claim, since balances will be migrated with the state snapshot.
The migration to EON 2.0 will involve the following key steps and features:
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Communication Assurance & Transparency.
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We will ensure transparent and timely communication with the entire ZEN community, ecosystem partners, and other stakeholders throughout the migration process.
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Before any significant actions are taken, detailed announcements will be made to explain the changes, the reasons behind them, and their impact.
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Disconnect EON from the Horizen Mainchain (ZEND).
- Remove the ability to transfer ZEN between EON and ZEND by disabling forward and backward transfers.
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Snapshot State.
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Take comprehensive state snapshots of both EON and ZEND.
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Captures all relevant data to ensure a seamless transition to EON 2.0.
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This means that existing smart contracts on EON will be transitioned over, including $ZEN in current liquidity pools.
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No action is needed by $ZEN holders.
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Ability for anyone to independently verify the integrity of both snapshots.
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Transition Exchanges, DEXs, partners.
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Allow a period of time to transition exchanges, DEXs, and partners.
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This would be a short period of time, on the order of hours, not weeks or months.
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Launch EON 2.0 Chain.
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Launch EON 2.0 genesis block from EON 1.0 state, maintaining all deployed smart contracts, storage and account balances, but not carrying over transaction history.
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Expose ZEND state through a precompile in EON 2.0.
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Prolonged Claim Window.
- Eligible users can claim their old Mainchain $ZEN by proving the ownership of their address.
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Migration Support.
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Provide comprehensive support to assist with the transition.
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Monitor the new network for any issues and address them promptly.
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Continue to engage with the community to gather feedback and improve EON 2.0 even further.
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Rationale
The Horizen Foundation currently engages Horizen Labs as its technical service provider for Mainchain Horizen and EON. The Horizen Foundation can leverage this existing relationship to utilize the expertise of Horizen Labs to support large and expansive initiatives. This would avoid delays and incurring additional costs, such as legal fees.
Backwards Compatibility
EON 2.0 will ensure backward compatibility to provide a smooth transition for existing $ZEN holders and EON developers, including incentives, emissions, staking, partner integrations, exchange continuity, and EVM compatibility.
Security & Privacy Concerns
The migration path has been designed with a strong emphasis on security. The snapshot-based approach ensures data integrity and minimizes the risk of data loss or corruption. By requiring proof of ownership, the manual claim process for ZEN balances further enhances security. EON 2.0’s use of Rust ensures reliable performance and safety, strengthening the overall security of the ecosystem.
Estimated Timeline and Cost
Blockchain migrations are complex undertakings that require meticulous planning and execution to ensure a smooth transition. We recognize the critical nature of this process and are committed to maintaining our reputation for high-quality software.
The migration is designed to be thorough and efficient, with an estimated timeline of roughly 8 months and a projected development cost of $1.5MM - $2.5MM from the start of development to Mainnet. Additional details are illustrated in the Gantt chart below. Considering the typical duration and expense of blockchain migrations, it is comparable to other similar migrations. For instance, Ethereum’s transition from Proof-of-Work to Proof-of-Stake consensus spanned over several years. We are dedicated to allocating the necessary resources and attention to detail to ensure the migration is handled correctly, emphasizing our commitment to quality and community trust.
Figure 3: High-level Gantt chart of activities for the migration of $ZEN and EON.