What's Opside

Opside is a decentralized ZK-Rollup-as-a-Service (ZK-RaaS) network, founded on the modular blockchain concept. By developing a sophisticated three-layer blockchain architecture, Opside combines the strengths of Proof-of-Stake (PoS) and Proof-of-Work (PoW) consensus mechanisms. This innovative design offers Web3 developers a robust and feature-rich zkEVM chain, which can be effortlessly generated with just a single click.
In the realm of scalability, the Layer 2 (L2) concept is widely recognized. However, L2's limitations stem from its inability to effectively integrate diverse hardware resources, including data availability, zero-knowledge proof (ZKP) computational capabilities, and peer-to-peer (P2P) nodes. This has given rise to the modular blockchain concept. Opside's innovative three-layer architecture builds upon the L2 foundation by seamlessly incorporating various modules and offering an external Zero-Knowledge-Rollup-as-a-Service (ZK-RaaS) platform.

• L1, Public Chain: Examples include Ethereum, BNB Chain, and Polygon.

• L2, Opside Chain: Opside delivers expansive decentralized consensus, data availability, and zero-knowledge proof (ZKP) computational capabilities. All transactions and data generated on the chain undergo validation and storage on Layer 2 (L2). As a result, transactions are executed rapidly, and fees remain minimal.

• L3, Rollup Layer: Rollups offload resource-intensive computations from the chain, thereby enhancing scalability. Opside offers a diverse range of Zero-Knowledge-Rollup Software Development Kits (SDKs), particularly zkEVM, which encompass Polygon Hermez, Scroll, Taiko, zkSync, and more. Developers can effortlessly deploy their own ZK-Rollup projects on Opside's Layer 3 (L3) with just a single click, while the decentralized Opside network supplies all necessary hardware resources.

Various layers are interconnected through distinct cross-chain bridges, enabling assets to be seamlessly transferred from Layer 1 (L1) to Layer 2 (L2) or Layer 3 (L3).

ZK-RaaS

ZK-RaaS (ZK-Rollup as a Service) refers to providing a one-click generation service for ZK-Rollups.

Opside provides a general ZK-Rollups SDK, which developers can use to easily deploy ZK-Rollups projects on Opside L3. Opside L3's ZK-Rollups are managed by a system contract, including registration, suspension, and cancellation. Developers can rent a Rollup slot with a certain amount of IDE (Opside token) to obtain a ZK-Rollup. This concept is similar to Parachain slots in Polkadot, but Opside L2 and L3 share the same consensus and data availability layer, resulting in higher security, more decentralized maintenance costs, and lower costs.

Upon renting a Rollup slot, developers obtain an independent execution environment, akin to possessing a zkEVM chain. They maintain full control over the ZK-Rollup, allowing customization of the economic model, including gas token selection. Developers have the flexibility to adjust the gas fee, even reducing it to zero, ensuring users are not burdened with any charges. Moreover, cross-rollup communication is feasible between various ZK-Rollup projects on Layer 3 (L3).

Developers need not incur any hardware expenses. All essential hardware resources, such as data availability, sequencer, and zero-knowledge proof (ZKP) computing power, are supplied by the decentralized hybrid consensus of Proof-of-Stake (PoS) and Proof-of-Work (PoW) mechanisms.

PoS & PoW Hybrid Consensus

ZK-Rollup boasts several advantages over OP-Rollup, including enhanced security, no trust requirements, and faster withdrawals. A key technical difference is that ZK-Rollup necessitates robust ZKP computing power to support zero-knowledge proof generation.
In the future, the Opside network may comprise hundreds or thousands of ZK-Rollups, collectively forming the Rollup Layer, which will generate substantial demand for ZKP computation. To address this, it is essential to incentivize miners to participate in and contribute to the ecosystem.
With Ethereum's transition from Proof-of-Work (PoW) to Proof-of-Stake (PoS), numerous Ethereum miners have become obsolete, representing a market value of approximately $12 billion. As ZK-Rollup technology matures, ZKP generation requires significant hardware and mining equipment, such as FPGAs and GPUs. Opside's mixed consensus of PoS and PoW not only employs the PoS mechanism to motivate validators to provide data availability but also utilizes PoW to encourage miners to supply ZKP computing power. This approach offers a comprehensive hardware solution for ZK-Rollup and represents one of Opside's core ideas. All participants, including users, developers, node operators, and miners, can benefit from the Opside economic model.
Opside aims to not only allow ZK-Rollup to inherit the security of previous layers but also the degree of decentralization. Ethereum, currently the largest decentralized network globally, has over 500,000 nodes providing massive decentralization. Thanks to data sharding technology, these nodes will also offer substantial data availability in the future. This is one reason why Opside has chosen to enhance the PoS consensus based on ETH 2.0.
Opside anticipates hosting more than 100,000 nodes. To achieve a similar level of decentralization for Rollup, a viable strategy involves having the Opside Chain's block proponent propose blocks for the Rollup Layer. This approach separates builders and proposers for the Rollup Layer: builders are supported by an unlicensed P2P network, and proposers follow the Layer 2 block proposer. This eliminates the availability risks associated with a single node and offers resistance to Miner Extractable Value (MEV) and censorship.

The hybrid PoS & PoW consensus entails the following division of labor:

Layer 2 (L2):

• PoS: Opside will adopt and improve upon ETH 2.0's PoS, resulting in a consensus layer with over 100,000 validators. Anyone can stake IDE tokens to become a validator. Additionally, Opside's PoS is provable, with validators periodically submitting PoS proof to Layer 1. Validators can earn block rewards and gas fees in Layer 2.

Layer 3 (L3):

• PoS (Sequencer): The validator proposes not only layer 2 blocks but also layer 3 blocks(i.e. data batch); that is, the validators are also the sequencers of the native rollups in layer 3. Sequencers can earn the gas fee from the transaction in layer 3 transactions.

• PoW (Prover): Anyone can be the prover of a native rollup as long as it has enough computing power for ZKP computation. Provers generate ZK proofs for each native rollup in layer 3. A prover generates ZK proof for each block of layer 3 submitted by sequencer according to the PoW rules.

A ZK-Rollup is analogous to a computer with two core components: a hard drive and a CPU. The data availability provided by PoS resembles the hard drive, while the computing power offered by PoW is akin to the CPU. Opside seeks to strike a balance between PoS and PoW, enabling each role to fully realize its value and benefit while providing improved performance and user experience for the large-scale ZK-Rollups network.
Achieving this balance will ensure that the Opside network can efficiently support the massive demand for ZKP computation generated by a vast number of ZK-Rollups. By effectively leveraging the strengths of both PoS and PoW mechanisms, Opside can create a robust and sustainable ecosystem that caters to the needs of all its participants, including users, developers, node operators, and miners.
As Opside continues to grow and evolve, it will play a crucial role in promoting the adoption of ZK-Rollup technology and fostering a decentralized, scalable, and secure environment for blockchain applications. This comprehensive approach will contribute to the long-term success and widespread use of ZK-Rollups in the blockchain landscape.

Token supply and demand

The allocation details for IDE (Opside token) are as follows: A maximum of 10 billion IDE will be minted. 10% is allocated for venture funding, 14% for the Opside team and contributors, and 15% for the community, which includes early testers, ecosystem project developers, and potential future airdrops. 28% is designated for the foundation to support ecosystem development, follow-up financing, and other purposes. The remaining 33% serves as rewards for validators and miners who provide data storage services, generate zero-knowledge proofs, maintain blockchains, and execute contracts. The token allocation chart is as follows:

In accordance with the hybrid PoS and PoW consensus, the block reward is divided into two parts, allocated to validators and miners respectively. During the Pre-Alpha testing network stage, the temporary block reward ratio for PoS and PoW is fixed at 1:2, meaning 11% of the IDE is assigned to validators, while 22% is designated for miners. In the future, this ratio will be dynamically adjusted based on the demand and supply of ZKP computational power across the entire network.

The reward of PoS

As mentioned earlier, Opside employs a PoS consensus based on an enhanced version of ETH 2.0. To participate as a validator, users must deposit a certain amount of IDE into the deposit contract and run three separate pieces of software: the execution client, consensus client, and validator. Validators are responsible for verifying the validity of new blocks propagated through the network and occasionally creating and propagating new blocks themselves. If a validator behaves dishonestly or negligently, the staked IDE will be forfeited.

Under PoS, Opside has a fixed block production rate, with time divided into slots (12 seconds) and epochs (32-time slots). In each slot, a randomly selected validator serves as the block proponent, responsible for creating new blocks and sending them to other nodes on the network. Additionally, in each slot, a committee of validators is randomly chosen to determine the validity of the proposed block using their votes. For the exact mechanism, please refer to ETH PoS.

Opside plans to support EIP-4844 in the Alpha test network, utilizing Data Availability Sampling (DAS) to ensure that ZK-Rollup provides transaction data after execution without overburdening individual nodes. Validators randomly sample the transaction data in the blob to verify that all data is present. This technique can also ensure block producers make all their data available to secure light clients. Under Proposer-Builder Separation (PBS), only the block builder needs to handle the entire block, while other validators use data availability sampling for verification.

Opside will differ in some specific parameters, which readers can find in the codebase.

Overall, staking simplifies participation in network protection and promotes decentralization. Validator nodes can be run on standard laptops, and some proxy staking pools even allow users to stake without a sufficient IDE balance.

The Rewards of PoW

In Opside's L3, or Rollup Layer, each Web3 application can have a dedicated ZK-Rollup. To support the extensive hardware resources required by numerous ZK-Rollups, Opside provides a unified ZKP computation marketplace, alongside validators offering data availability, to generate ZKPs for these ZK-Rollups. This constitutes Opside's PoW mechanism.

Reward share calculation for a single rollup sequence

In the Pre-Alpha phase, only one sequence can be submitted per Rollup within an L2 block (which may contain multiple blocks of that Rollup). All sequences share the PoW reward of the current block equally, based on the number of registered Rollup slots. This means that if there are currently 64 registered rollup slots, each sequence in an L2 block receives 1/64th of the PoW reward. Some rollups may not submit sequences in some blocks, resulting in lower actual PoW inflation.

In the future, individual sequences will be priced differently based on workload estimates considering factors such as ZK-Rollup type, transaction quantity, and gas usage.

Two-step submission of ZKP

The PoW reward share obtained by a sequence is allocated to the submitters of valid ZKPs, those are, miners, according to certain rules. From a technical perspective, when Rollup's smart contract validates ZKP, it may trigger an on-chain attack if the original proof data is submitted. For example, after a certain prover calculates the ZKP, the transaction is broadcast to the transaction pool, and the attacker can see the raw proof data, and the attacker can set a higher gas fee to send the transaction, thus prioritizing the packing into the block to get the PoW reward. To prevent malicious attacks, Opside proposes a two-step submission mechanism for ZKP verification.

1) Submit the hash

• For a certain sequence, after the prover calculates ZKP, it calculates the (proof / address) hash and submits the hash and address to the contract, where proof is the proof of a certain sequence and address is the address of the prover, who must stake in advance

• Assuming that the first prover submits the hash in the block T, other prover submissions of hash are accepted up to the block T+10, with no limit on the number. No new prover will be accepted to submit hash in block T+11 and after

2) Submit ZKP

• After block T+11, any prover is allowed to submit ZKP. as long as one ZKP passes validation, then all submitted hashes are verified. Any prover that passes the validation gets a PoW reward, which is distributed in proportion to the amount staked by the miner.

• If no ZKP passes validation until block T+20, all prover's submitted hashes are forfeited 1000 IDE, at which point the sequence is reopened to allow new hashes to be submitted

For example, suppose the PoW reward for each L2 block in Opside chain is 128 IDE, and there are 64 Rollup slots in total, then the PoW reward allocated to each Rollup sequence is 2 IDE. Then the PoW reward for A, B, and C is 0.4 IDE, 1 IDE, and 0.6 IDE, respectively.

Prover staking and slashing

In order to avoid malicious behavior against prover, prover needs to register in a special system contract and stake at least 100000 IDE. If the current staking quantity is less than the threshold, no hash and ZKP submission will be allowed. Prover's reward for ZKP submission will also be distributed in proportion to the staking quantity, thus avoiding the malicious behavior of prover who submits ZKP multiple times.
Different levels of penalties will be applied when the prover does the following:

• If the prover submits the wrong hash, the penalty will be 10000 IDE

• For a sequence, if no corresponding ZKP is verified, all provers who submitted a hash will be slashed 1000 IDE

The slashed IDEs will be burned.

For more details and considerations on ZKP's two-step submission mechanism, readers are referred to the official documentation. prover pledges and the exact number of penalties are subject to change in the future.

Rollup slot rental for developers

Opside offers a ZK-Rollup launch platform for developers, allowing them to register a Rollup slot with one click to create their own ZK-Rollup. The Opside decentralized network provides all necessary hardware resources for the ZK-Rollup. Developers only need to pay a certain rent for the Rollup slot to the Opside network, which is subsequently burned.

In addition to a fixed rent amount, developers can provide additional ZKP subsidies for their ZK-Rollup to incentivize miners to supply computational power. This feature will be introduced in the Alpha testnet.

Readers can find specific rent and subsidy rules and parameters in the official documentation or codebase. These measures contribute to the ongoing growth and optimization of the Opside network, fostering a thriving ZK-Rollup as a Service ecosystem.

Governance and Development

The functionality and performance of the Opside network will progress over time, with several high-priority examples outlined below:

• Dynamically scaling PoS to PoW reward allocation based on ZKP computation supply and demand across the network

• Enhancing data storage capacity for the entire Rollup Layer through validators' data slicing and data availability sampling, thereby accommodating a broader ZK-Rollup ecosystem

• Separating the proposer and builder of Rollup allows Layer 3 to share Layer 2's validator as the block proposer, inheriting the decentralization of the previous layer

• Optimizing the staking and slashing mechanism for miners to encourage the provision of consistent and stable ZKP computing power

• Developers subsidizing ZKP generation for their respective Rollups to incentivize miners to supply computational power

• Establishing a personalized pricing mechanism for Rollup batches based on workload estimation, considering factors such as ZK-Rollup type, transaction quantity, and gas usage

These enhancements will significantly increase Opside's network utility, promoting the long-term development and prosperity of ZK-Rollup as a Service.

Following the launch of the Opside main network, an Opside DAO (Decentralized Autonomous Organization) will be established, featuring rational processes and mechanisms for collectively determining the network's future. All updates to the Opside master network's parameters and mechanisms will be decided through the Opside DAO. It is essential to emphasize that Opside represents a collaboratively built economy that evolves over time. Future improvements will take the form of DAO proposals, detailing how these solutions will benefit the long-term interests of the Opside economy and each participant category. As the network expands, it is crucial to establish an economy that can operate independently and robustly without extensive tools and subsidies.