# Optimism L2 Blockchain By [Web3 World ](https://paragraph.com/@web3-world-2) ยท 2023-03-24 --- **_OptimismPBC: A Comprehensive Overview of a Layer 2 Blockchain Solution_** **_Introduction:_** The Ethereum blockchain has been a revolutionary technology that has enabled the creation of decentralized applications (dApps) and smart contracts. However, the scalability and throughput of the Ethereum network have been a major concern for developers and users alike. The network is notorious for its high gas fees and slow transaction processing times, which have led to network congestion and delays. OptimismPBC is a Layer 2 scaling solution that aims to solve these issues by leveraging an optimistic rollup design. The platform creates a separate blockchain, the Optimistic Virtual Machine (OVM), which processes transactions off-chain before they are ultimately settled on the Ethereum mainnet. This report provides a detailed overview of the technical details, architecture, consensus mechanisms, and benefits of OptimismPBC. **_Architecture:_** The OptimismPBC architecture consists of several key components that work together to create a seamless user experience. These components include the sequencer, fraud proof game, and the OVM. The sequencer is a trusted entity that is responsible for publishing batches of transactions to the Ethereum mainnet. The sequencer ensures the validity of transactions before they are published, making the process more efficient and secure. The fraud proof game is a mechanism that incentivizes users to report any fraudulent behavior that may occur within the OptimismPBC system. This mechanism ensures the security and integrity of the system. The OVM is a separate blockchain that processes transactions off-chain before they are ultimately settled on the Ethereum mainnet. The OVM is responsible for executing smart contracts and validating transactions. By processing transactions off-chain, the OVM allows for a much higher throughput than is possible on the Ethereum mainnet. **_Consensus Mechanism:_** OptimismPBC uses a modified version of the Plasma Cash protocol as its consensus mechanism. The Plasma Cash protocol is a Layer 2 scaling solution that operates by creating a separate blockchain, or plasma chain, that is anchored to the Ethereum mainnet. Transactions are processed off-chain on the plasma chain before they are ultimately settled on the Ethereum mainnet. OptimismPBC's version of the Plasma Cash protocol differs from the original protocol in several key ways. One major difference is that OptimismPBC's version allows for the creation of arbitrary smart contracts, whereas the original protocol only supports simple payments. This allows for a wider range of applications to be built on top of the OptimismPBC platform. Benefits OptimismPBC offers several key benefits over traditional Ethereum transactions. First and foremost, OptimismPBC allows for significantly faster transaction processing times. Transactions are processed off-chain on the OVM before they are ultimately settled on the Ethereum mainnet, allowing for a much higher throughput than is possible on the mainnet alone. In addition to faster transaction processing times, OptimismPBC also offers reduced transaction fees. Because transactions are processed off-chain, they do not require the same level of computation as on-chain transactions. This results in lower fees for users. Finally, OptimismPBC offers increased scalability for the Ethereum network as a whole. By processing large numbers of transactions off-chain, OptimismPBC can help to alleviate congestion on the Ethereum mainnet and reduce the number of failed transactions. This makes the platform ideal for use cases such as decentralized exchanges, gaming platforms, and other applications that require fast and efficient transaction processing. Technical Details OptimismPBC uses a rollup-based design to process transactions off-chain. This design allows for the bundling of multiple transactions into a single batch, which is then processed on the OVM. Once the transactions have been processed and validated, the batch is then published to the Ethereum mainnet. One of the key features of the OptimismPBC platform is its use of fraud proofs to ensure the security and integrity of the system. The fraud proof game incentivizes users to report any fraudulent behavior that may occur within the system. If a user detects fraudulent behavior, they can submit a fraud proof to the system, which will then be validated by the fraud proof game. If the proof is valid, the user is rewarded with a portion of the transaction fees. The OptimismPBC platform also supports the use of arbitrary smart contracts. This allows developers to create a wide range of decentralized applications that can be built on top of the platform. Smart contracts can be written in Solidity, the same programming language used for Ethereum smart contracts. **_Conclusion_** OptimismPBC is a Layer 2 scaling solution that offers significant benefits over traditional Ethereum transactions. The platform allows for significantly faster transaction processing times, reduced transaction fees, and increased scalability for the Ethereum network as a whole. OptimismPBC's use of the rollup-based design and fraud proof game ensures the security and integrity of the system. The platform also supports the use of arbitrary smart contracts, allowing for a wide range of decentralized applications to be built on top of the platform. Overall, OptimismPBC is a promising solution that has the potential to significantly improve the scalability and usability of the Ethereum network. --- *Originally published on [Web3 World ](https://paragraph.com/@web3-world-2/optimism-l2-blockchain)*