TL;DR: Polymer is building Ethereum’s interoperability hub, enabling interoperability between all Ethereum rollups via native IBC technology powered by Ethereum security.
Polymer itself is an Ethereum rollup consisting of the following building blocks:
Settlement: OP Stack provides Ethereum’s settlement and chain-derived logic
Execution: Cosmos SDK provides native IBC interoperability for connected rollups
Data availability: EigenDA provides scalable data availability
Proof: OP Stack’s modular failure proof system provides:
Interactive Fraud Proofs: Interactive Verification Game (IVG) played on MIPS (Cannon) or RISC-V (Asteric) Fault Proof VMs
ZK Validity Proof: RiscZero
Interoperability – where are we now?
Since Ethereum launched in July 2015 as the first blockchain to support arbitrary application logic, its broad community of developers, investors, and enthusiasts has built one of the strongest networks in the cryptocurrency space. Ethereum has become fertile ground for experimentation with a wide range of decentralized application types, from decentralized finance to NFTs and more. Moreover, Ethereum not only provides the world with decentralized computing, but also provides a censorship-resistant currency and a deflationary store of value.
While Ethereum is the largest and most widely used decentralized network, scalability has been a persistent barrier to growth. However, Layer 2s have partially alleviated the scaling issues and shown progress, particularly in how they enable Web 2 scaling and user experience, but they come with tradeoffs. Sharded execution across these Layer 2s achieves scalability, but at the cost of creating isolated execution environments that fragment liquidity, confuse end users, and complicate the developer journey.
With no standard native messaging solution across these chains, secure composability across Layer 2 has become one of the most significant issues plaguing Ethereum, and will continue to grow as Layer 2 launches and scales. Early interoperability solutions have attempted to address this problem by building token bridges, but previous bridges have been insecure and susceptible to massive hacks (see here, here, and here for just a few examples). All existing Arbitrary Messaging Bridges (AMBs) are implemented as smart contracts, and different implementations have led to fragmented composability.
How do we solve these problems?
Polymer: Ethereum’s Interoperability Hub
With experience building interoperability and cross-chain applications on Ethereum since 2020, the Polymer team is excited to announce our latest designs and architectures for connecting Ethereum, rollups, and more.
Polymer is not a third-party bridge, but rather a layer 2 rollup that specifically acts as an interoperability hub for Ethereum by offering IBC (Inter-Blockchain Communication) as a feature of Ethereum and establishing connections to integrated layer 2. This domain-specific interoperability model improves upon the non-domain-specific approaches taken by predecessors. Ethereum itself is validating IBC executions on behalf of its rollups. We expect domain-specific interoperability to become increasingly popular in the short term.
Polymer allows applications to have composability between Ethereum rollups and access to IBC’s growing network of applications and feature set, including inter-chain accounts, application callbacks, and more.
Polymer takes a hybrid approach, combining the settlement capabilities of the OP stack with the developer experience and native interoperability of the Cosmos SDK. Polymer also leverages Eigenlayer’s data availability, extending the Ethereum network’s data availability throughput by 10 mb/s and making more optimizations.
While Layer 2s are recognizing the need for interoperability by building zero-knowledge provers and shared ordering, these efforts are mostly isolated and limited to their own frameworks and only address a portion of the interoperability problem. We believe Ethereum and its rollups lack a unified interoperability standard that addresses the pain points of every multi-ecosystem stakeholder. Polymer establishes IBC as the interoperability standard for the entire industry.
IBC Construction
IBC is a blockchain interoperability solution that allows arbitrary data transfer between blockchains connecting over 100 chains and enabling over $30 billion in transfers. It is the most battle-tested interoperability protocol in the industry today. No other interoperability protocol has achieved the scale of success that IBC has, connecting over 100 chains and enabling over $30 billion in transfers. Recently, it has securely facilitated over $1.5 billion in transaction volume per month. IBC is designed with key attributes that align with the core ethos of blockchain:
Trusted Neutrality: IBC is open source software that anyone can contribute to, rather than a product of any single for-profit company. It is developed as a public product, and no in-protocol rent extraction chains, applications, and smart contracts can use IBC for free.
No vendor lock-in: IBC enables application protocols to easily switch between security models and interop providers. For example, there is no need to roll back and migrate tokens when switching interop providers. IBC channel upgrades can switch the underlying connection to a new group, preventing vendor lock-in.
Modular security: IBC is designed to ensure the highest standards of default security while allowing developers the flexibility to reduce security for less critical use cases. It can be configured to use consensus validating light clients, multi-signers, or even local bridge rollups for validation.
Providing a strong feature set: IBC provides key features that builders need but are not widely used in competing solutions. Developers can use IBC to build not only token transfers, but also inter-chain accounts (i.e. the ability to allow a module or contract on one chain to control an account on a remote chain), inter-chain queries, and asynchronous communication between smart contracts on different chains. Imagine using a single private key to control your wallet on all the chains where you own assets, and how this would simplify the user experience for the average user.
OP Stack Build
Polymer joins a long list of blockchains that leverage OP Stack as their settlement infrastructure, including Base, Zora, and others. We decided to use OP Stack as the settlement framework for the Ethereum Interoperability Hub because it provides:
Flexibility, Scalability, and Performance: Polymer differs from other Rollups in that it is focused on meeting the interoperability needs of applications on other Rollups, rather than executing decentralized applications themselves. This departure from the vast majority of rollup functionality requires great flexibility to build. OP Stack also has higher capacity and throughput than the Ethereum mainnet, which is necessary to support the interoperable rollup world we envision.
Decentralization through a thriving collaborative ecosystem: OP Stack is building a powerful network and combining engineering talent from OP Labs, Coinbase, and various open source contributors to accelerate the decentralized development of super chains.
Ethereum Security and Consistency: Ethereum has the right combination of technical, cultural, and economic elements to continue to grow the most powerful decentralized ecosystem in crypto. Our team at Polymer Labs is committed to driving Ethereum’s scaling roadmap forward, especially expanding interoperability.
Eigenlayer build
EigenDA uses the same underlying asset to increase the data bandwidth of the Ethereum network for security. Here is a detailed explanation of why we chose to use EigenDA for data availability:
Ethereum Security: Domain-specific interoperability hubs should borrow as much security as possible from the same sources as the Rollups they connect to. For Rollups that inherit Ethereum security, the safest option is to use Ethereum DA. The next best option is to leverage EigenDA, which borrows security from a subset of Ethereum’s stake and validator set.
Scalability: EigenDA significantly improves the data availability throughput of the Ethereum network. EigenDA’s cost model is also more flexible, allowing for more affordable data availability services to support high-throughput use cases such as cross-chain interoperability.
Bringing it all together
We carefully selected this approach because we believe IBC is the right solution for the Ethereum ecosystem. As the highest value settlement layer in cryptocurrency, Ethereum provides the most security for cross-chain transactions through Polymer, rather than any alternative solutions that rely on validator sets or blind trust in centralized off-chain entities. As the number of L2s on Ethereum proliferates, the need for domain-specific interoperability hubs like Polymer grows. Polymer also leverages EigenDA to increase the scalability and cost-effectiveness of the solution.
Polymer plays a key role in Ethereum's scaling story, enabling builders to create seamlessly composable applications across Ethereum rollups and other areas with the best trust models. The interoperable future we are building is the future of cryptocurrency achieving mass adoption. In this future scenario, users can easily store their assets on-chain, leverage the best applications no matter which chain they live on, and navigate cryptocurrencies without complex user experience barriers.
Integrating Ethereum and Cosmos
Ethereum and Cosmos are values-aligned and have established foundational innovations for blockchain technology. Both have made great strides in advancing our industry, but have done so by working in silos. Polymer changes this by establishing a path for advancements made in Cosmos to be deployed directly into the Ethereum ecosystem, including bringing IBC to Ethereum.
