For a Layer 2 network managing billions of dollars in assets, the speed of transaction finality not only shapes user experience but also directly impacts capital efficiency. Currently, Base holds a total value locked (TVL) of approximately $4.644 billion, with a 24-hour DEX trading volume reaching $862 million, making it one of the most active Layer 2 networks in the Ethereum ecosystem. In its original optimistic rollup design, withdrawals from Base back to Ethereum mainnet required a challenge period of up to 7 days—during which anyone could dispute the validity of a transaction. While this mechanism secures the network through game-theoretic assumptions, it also means funds can be locked for up to a week before becoming freely available. To achieve predictable and rapid finality, the network must fundamentally change its verification approach. Zero-knowledge proofs (ZKPs) offer a viable solution: replacing time-based windows with cryptographic proofs, shifting the trust model from "waiting for challenges" to "mathematical verification," and dramatically reducing the waiting time for funds.
How Do Multi-Proof Systems Reshape Layer 2 Finality?
The core of the Azul upgrade isn’t simply swapping optimistic proofs for ZKPs; it’s about building a multi-proof system. The new architecture runs two parallel verification channels: zero-knowledge proofs generated by SP1 and TEE proofs produced by a trusted execution environment. Either mechanism can independently finalize transaction proposals, and when both agree, withdrawal settlement times can be cut to just one day. This design directly addresses the long-standing trade-off in Optimistic Rollups—longer challenge periods mean lower capital efficiency, while shorter ones increase the attack window. The multi-proof system provides redundant security through dual validation: it’s difficult for errors or attacks in one channel to compromise the other. Moreover, if the two proofs conflict, the permissionless ZK proof overrides the permissioned TEE proof, giving the system on-chain fault detection and handling capabilities—a key step toward Stage 2 decentralization as defined by L2Beat.
Architectural Independence from the OP Stack: The Strategic Value of a Unified Codebase
In February, Base announced its move from the Optimism OP Stack to its own unified codebase—far more than a simple tech swap. Under the OP Stack framework, Base’s node software versions, upgrade cadence, and data packaging were all subject to external dependencies. Independence gives the Base engineering team full control over technical decisions—from hard fork frequency to consensus layer optimization—all managed internally. The direct benefits of a unified codebase are already evident in the Azul upgrade: the number of empty blocks dropped from about 200 per day to just 2, a reduction of nearly 99%. During testnet phases, the network has handled transaction bursts of up to 5,000 TPS. More importantly, this independent architecture allows Base to prioritize ZK proof integration on its own timeline, rather than waiting for the OP ecosystem’s unified roadmap. Centralized control and multi-proof security models are not contradictory—coordinated management of core infrastructure actually provides the engineering foundation needed for a robust multi-proof system.
How Does the Leading Layer 2 by TVL Choose Its Verification Path?
By TVL, Base is currently the largest Ethereum Layer 2 network, commanding a market share of about 46.36%. For networks of this scale, changing the verification mechanism isn’t just a technical upgrade—it’s a careful migration involving hundreds of protocols and tens of millions of user assets. This upgrade takes a hybrid approach—retaining the optimistic rollup framework while adding a ZK proof channel, allowing both systems to coexist long-term. It’s a pragmatic evolution: rather than hastily dismantling existing infrastructure, Base is layering on new security guarantees to gradually drive system transformation. SP1, the largest and most secure zkVM to date, has generated millions of proofs for over 35 clients including Polygon, Mantle, and Lido, collectively securing about $4 billion in assets. By choosing SP1—already proven in large-scale security deployments—to verify its $7.4 billion in deposits, Base demonstrates a robust upgrade path built on validated infrastructure.
Performance and Security: How Does the SP1 zkVM Enable Real-Time Proofs?
From a technical standpoint, the true integration of ZK proofs into Layer 2 daily operations hinges on proof generation efficiency and cost. In testing, SP1 Hypercube can generate zero-knowledge proofs for 99.7% of Ethereum mainnet blocks within 12 seconds. This performance forms the mathematical foundation for real-time Layer 2 block validation. Unlike traditional ZK solutions that require custom circuit design and hours-long proof generation, SP1 lets developers write programs in standard Rust, compile them to RISC-V, and generate ZK proofs directly—significantly lowering the barrier to ZK adoption. Crucially, all 62 core RISC-V opcodes in SP1 have undergone comprehensive formal verification by Nethermind Security and the Ethereum Foundation, providing mathematically sound security guarantees. For networks safeguarding over $4 billion in assets, the proof system’s security must meet the highest audit standards—and SP1 delivers industry-leading assurance on this front.
Strategic Outlook: Does Azul Signal a Full Shift to ZK Rollup for Base?
The current multi-proof design is not the endgame. Azul is explicitly defined as an intermediate step toward full ZK proof adoption, with the long-term goal of near-instant withdrawal finality. The roadmap includes several key milestones: integrating more ZKVM solutions for proof diversity, ongoing optimization of real-time proof performance, and gradually reducing finality times as technical reliability improves. Notably, introducing a hybrid TEE and ZK architecture at this stage is itself a progressive security strategy—an attacker would have to compromise two independent security systems simultaneously to disrupt the fast withdrawal channel. This security model not only provides redundancy for the current upgrade but also builds engineering experience and real-time data for a future transition to a fully ZK-based verification system.
From Ecosystem Debate to Technical Implementation: A Verifiable Architectural Evolution
Base’s decision to introduce zero-knowledge proofs is not an isolated event—it follows the logic of architectural autonomy established by its move away from the OP Stack. Market discussions around this shift often focused on economic incentives—Base, as the largest contributor of gas fees (about 96.5%) in the OP ecosystem, was seen as potentially disrupting Optimism’s revenue model by going independent. However, the technical path of the Azul upgrade demonstrates that the value of independence lies not only in economic autonomy, but more importantly in the ability to dynamically integrate infrastructure-heavy upgrades like ZK proofs. As security and compatibility demands grow, a unified codebase empowers the engineering team to integrate at the protocol level rather than waiting for third-party architecture updates. This is an engineering trade-off: by centralizing infrastructure control, Base can rapidly deploy complex security features. The Azul upgrade is early proof of this approach in practice.
Potential Trade-Offs and Long-Term Challenges of a Hybrid Verification System
Every security architecture adjustment introduces new risk dimensions. Unlike most ZK rollups, Base’s current use of TEE proofs depends on trusted execution environments provided by hardware manufacturers, introducing a degree of reliance on hardware vendor trust. Although the design specifies that ZK proofs have final authority in the event of a conflict with TEE proofs, the security of the TEE channel still rests on the trustworthiness of the hardware supply chain. Additionally, generating ZK proofs requires significantly more computing resources than optimistic rollup challenge mechanisms. Whether the ongoing cost of proof generation remains manageable depends on the pace of SP1’s optimization in real-world mainnet environments. The Azul upgrade also includes a major overhaul of the core client stack, discontinuing support for multiple consensus and execution clients in favor of unified use of base-reth-node and base-consensus clients. While this streamlines node operations, it also introduces the risk of client centralization. As Base advances toward Stage 2 decentralization, balancing simplified operations with the need for multi-client coordination will remain an ongoing challenge.
Conclusion
With the Azul upgrade and its collaboration with Succinct, Base introduces a multi-proof architecture that adds a ZK proof channel to the optimistic rollup framework, reducing transaction finality from 7 days to just 1 day. This hybrid model accelerates the deployment of complex security features by centralizing infrastructure control, while building an engineering-validated bridge to a future full ZK rollup transition. The unified codebase independent of the OP Stack, the formally verified SP1 zkVM, and the redundancy of a multi-proof system together form a practical path for refining Layer 2 architecture across efficiency, security, and scalability dimensions.
FAQ
When will the Base Azul upgrade be deployed?
The Base Azul upgrade went live on testnet on April 22, 2026, with mainnet activation targeted for May 13, 2026. The collaboration with Succinct will be fully integrated as part of the Azul mainnet launch.
How is 1-day finality achieved?
When both a zero-knowledge proof generated by SP1 and a TEE proof from the trusted execution environment validate the same transaction proposal, Base can reduce withdrawal settlement to Ethereum mainnet to just 1 day. If the two proofs conflict, the permissionless ZK proof overrides the TEE proof, ensuring system security and finality.
Has Base fully transitioned to a ZK rollup?
Not yet. The current Azul upgrade implements a hybrid multi-proof system—TEE and ZK proofs operate in parallel. This is an intermediate step toward full ZK proof adoption, with the long-term goal of near-instant withdrawal finality as the technology matures.
What is SP1?
SP1 (Succinct Processor 1) is an open-source zero-knowledge virtual machine developed by Succinct Labs. It allows developers to write programs in standard Rust and generate verifiable ZK proofs without custom circuit development. As of May 2026, over 35 clients have used SP1 to generate millions of proofs, securing about $4 billion in assets.
How much in assets does this upgrade cover?
SP1 will be used to prove deposits of about $7.4 billion on Base. The network’s current total value locked stands at approximately $4.644 billion.
What other performance optimizations are included in the Azul upgrade?
Beyond the proof system update, the Azul upgrade unifies Base’s execution client as base-reth-node and introduces the base-consensus client, reducing empty blocks from around 200 per day to just 2, and handling transaction bursts of up to 5,000 TPS on testnet.
