Ethereum Foundation Pivots zkEVM Strategy to 128-Bit Provable Security, Announcing Key Milestones for Mainnet-Grade Robustness

The Ethereum Foundation (EF) has declared a pivotal shift in the development trajectory for zero-knowledge Ethereum Virtual Machines (zkEVMs), moving from an intense focus on proving speed to an uncompromising commitment to 128-bit provable security. This strategic reorientation comes after a year of unprecedented advancements in zkEVM performance, which saw proving latency dramatically reduced and costs significantly lowered, paving the way for the technology’s next critical phase: achieving mainnet-grade robustness and reliability.

The Rapid Evolution of zkEVMs: A Year of Unprecedented Speed

For the past year, the zkEVM ecosystem has been engaged in a vigorous sprint, aiming to overcome the significant computational hurdles associated with zero-knowledge proofs. This ambitious endeavor was largely guided by a "north-star definition" for real-time proving, established by the Ethereum Foundation in July 2025. The results of this concentrated effort have been nothing short of transformative, exceeding even optimistic projections and marking a major milestone for the technology.

Data compiled from various zkEVM teams and verified by independent analyses indicate a profound leap in efficiency. Proving latency, a critical metric for the speed at which transactions can be verified, plummeted from an average of 16 minutes to a mere 16 seconds. This 60-fold acceleration signifies a monumental improvement, bringing near-instantaneous verification capabilities to the forefront of blockchain scaling solutions. Simultaneously, the operational costs associated with generating these proofs witnessed a staggering 45-fold collapse, making the technology far more economically viable for widespread adoption. Furthermore, zkVMs, the underlying virtual machines powering zkEVMs, are now capable of proving an astounding 99% of all Ethereum blocks in under 10 seconds on target hardware. This achievement effectively validates the ecosystem’s capacity for real-time processing, addressing a primary bottleneck that previously hindered the practical deployment of ZK-rollups. These performance breakthroughs have laid a robust foundation, demonstrating that the technical challenges related to speed have largely been surmounted.

The Urgent Call for Unwavering Security: Addressing the "Elephant in the Room"

With the performance bottlenecks largely cleared, the Ethereum Foundation is now directing the ecosystem’s attention to what it identifies as the "elephant in the room": security. The successful acceleration of proving capabilities has set the stage for the next, arguably more critical, phase: ensuring that zkEVMs are not only fast but also fundamentally secure enough to handle the immense value and trust inherent in the Ethereum mainnet. The journey towards a truly mainnet-grade infrastructure demands an unyielding focus on cryptographic soundness, especially given the catastrophic implications of any security vulnerability.

The Imperative of 128-Bit Provable Security

At the core of this strategic pivot is the demand for 128-bit provable security. Many current STARK-based zkEVM implementations, while innovative, often rely on mathematical conjectures that have yet to be rigorously proven. This reliance introduces a degree of uncertainty, as the security guarantees are contingent upon the validity of these unproven assumptions. Over the past several months, the field of STARK security has experienced significant scrutiny, with leading researchers mathematically disproving several foundational conjectures. Each such disproof effectively erodes the perceived security strength of systems built upon these assumptions; what might have been advertised as 100 bits of security could, in reality, be closer to 80 bits or even less. This erosion of security margins is unacceptable for a technology intended to secure billions of dollars in digital assets.

The Ethereum Foundation unequivocally states that the only viable path forward is through provable security. This means relying on cryptographic constructions whose security can be mathematically demonstrated, rather than conjectured. The target for this provable security is set at 128 bits, a standard widely recognized and recommended by global standardization bodies such as the National Institute of Standards and Technology (NIST SP 800-57pt1r5). This security level is not an arbitrary benchmark; it is validated by real-world computational milestones and endorsed by prominent figures within the blockchain community, including Ethereum co-founder Vitalik Buterin, who has consistently emphasized the importance of robust cryptographic security. Achieving 128-bit security provides a sufficient margin against known and anticipated attack vectors, including those from powerful state-sponsored adversaries.

For zkEVMs, particularly those aspiring to function as Layer 1 (L1) solutions or critical components within the broader Ethereum ecosystem, a soundness issue is not merely a bug; it represents a fundamental compromise. Unlike other security vulnerabilities that might affect specific applications or user accounts, a flaw in the cryptographic soundness of a zkEVM proof system could allow an attacker to forge valid proofs for invalid state transitions. This would empower malicious actors to mint tokens from nothing, arbitrarily rewrite the blockchain’s state, or steal vast sums of funds. Given that L1 zkEVMs are envisioned to secure hundreds of billions of dollars, the security margin is, as the Foundation stresses, "not negotiable." The integrity of the entire system hinges on the absolute certainty of its cryptographic foundations.

Ethereum Foundation’s Strategic Roadmap: Three Milestones for Mainnet-Grade Robustness

Recognizing the inherent tension between achieving high security levels and maintaining compact proof sizes – as more security typically implies larger proofs, which can strain Ethereum’s peer-to-peer network propagation capabilities – the Ethereum Foundation has outlined a clear, actionable roadmap with three critical milestones. These milestones are designed to guide zkEVM teams towards the mandated 128-bit provable security while ensuring proofs remain efficiently manageable.

Milestone 1: soundcalc Integration

• Deadline: End of February 2026
• Objective: To establish a standardized and consistent method for measuring zkVM security across the ecosystem. The Foundation has developed soundcalc, an open-source tool designed to estimate zkVM security levels based on the latest cryptographic security bounds and proof system parameters. This tool is envisioned as a living document, continuously updated to incorporate cutting-edge research and newly discovered attack vectors. By the specified deadline, all participating zkEVM teams are required to integrate their proof system components and all associated circuits with soundcalc. This integration will provide a common, transparent, and verifiable baseline for all subsequent security assessments, fostering an environment of shared understanding and accountability regarding security posture. Previous integrations, such as those documented in ethereum/soundcalc/issues/18 and ethereum/soundcalc/pull/21, serve as practical examples for teams.

Milestone 2: Glamsterdam

• Deadline: End of May 2026
• Objective: This milestone marks a significant intermediate step towards achieving the ultimate 128-bit security target. While specific technical details are left to be defined by the participating teams in collaboration with the Foundation, Glamsterdam is expected to focus on the demonstration of initial security improvements and optimizations. It will likely involve showcasing early implementations of new cryptographic primitives or architectural changes aimed at bolstering soundness, as well as providing preliminary evidence of progress towards reducing proof sizes without compromising security. Teams might present advancements in proof aggregation techniques or novel polynomial commitment schemes, indicating a clear trajectory toward the final security objectives. This phase will likely involve rigorous testing and peer review of these foundational changes.

Milestone 3: H-star

• Deadline: End of 2026
• Objective: H-star represents the culmination of the security-focused roadmap, with the overarching goal of achieving full 128-bit provable security for zkEVMs alongside optimized proof sizes suitable for reliable propagation across the Ethereum network. By this deadline, zkEVM implementations are expected to have robust, mathematically provable security guarantees, effectively mitigating the risks posed by reliance on unproven conjectures. This milestone will require comprehensive security audits, formal verification efforts, and a complete integration with soundcalc demonstrating adherence to the 128-bit standard. The successful completion of H-star will signify that zkEVMs are technically ready for widespread mainnet deployment, possessing the cryptographic integrity necessary to secure high-value transactions and state transitions.

Enabling Technologies and Methodologies for Robustness

The ambitious goals set forth by the Ethereum Foundation are deemed tractable thanks to recent breakthroughs in both cryptographic theory and engineering practices. Several key advancements are highlighted as crucial enablers for hitting these milestones:

• Compact Polynomial Commitment Schemes: Innovations like WHIR (Weakly Hiding Inner Product Argument with Recursion) offer more efficient ways to commit to polynomials, leading to smaller proof sizes without sacrificing security. This directly addresses the tension between security and proof size.
• Advanced Techniques: Methods such as JaggedPCS represent cutting-edge cryptographic tools that enhance the efficiency and security properties of proof systems.
• "Grinding" for Security: The concept of "grinding," often involving computational work to find proofs with specific properties (like a certain number of leading zeros in a hash), can contribute to increasing the security level of certain cryptographic primitives, effectively adding "bits of security" to a proof system.
• Well-Structured Recursion Topology: Modern zkEVMs are inherently complex, involving numerous circuits that interact and compose proofs through recursion. Each team often employs unique recursion strategies with intricate "glue" logic connecting various components. Documenting this architecture thoroughly and ensuring its soundness is paramount for the security of the entire system. A clear, verifiable recursion topology is essential for understanding and auditing the overall security guarantees. The Foundation emphasizes that meticulous design and documentation of these recursive structures are non-negotiable for achieving provable security.

The Path Forward: Stabilizing for Formal Verification

The strategic timing of this renewed focus on zkEVM security is deliberate. The Foundation recognizes that "securing a moving target is hard." By setting these definitive milestones and pushing for architectural stabilization, the ecosystem can transition to a phase where formal verification work, an area the Foundation has been actively investing in (as seen with initiatives like verified-zkevm.org), can reach its full potential.

The objective is that by the H-star deadline, the proof system layer of zkEVMs will have largely "settled." While not implying a complete cessation of innovation, this stabilization means that the core architectures, cryptographic primitives, and recursion strategies will be robust and well-defined enough to undergo rigorous formal verification. This process involves mathematically proving the correctness and security of critical components, finalizing cryptographic security proofs, and ensuring that technical specifications accurately match the deployed code. This foundational stability is an absolute prerequisite for realizing truly secure L1 zkEVMs capable of supporting the next generation of decentralized applications and financial systems on Ethereum.

Building Foundational Trust for a Resilient Future

A year ago, the prevailing question in the blockchain community revolved around the performance capabilities of zkEVMs: could they prove fast enough to be practical? That question has been resoundingly answered in the affirmative, with dramatic reductions in latency and cost. The new, more profound question is whether they can prove soundly enough – with absolute, provable cryptographic security – to warrant the immense trust required for mainnet-grade operation.

The Ethereum Foundation expresses strong confidence that this new challenge can be met. By shifting resources and focus, fostering collaboration, and leveraging cutting-edge cryptographic research and engineering, the ecosystem is poised to strengthen the very foundations upon which the future of Ethereum’s scalability and security will be built. The Foundation’s role in this next phase will include continued research and development into cryptographic security bounds, further enhancements to tools like soundcalc, and providing comprehensive support and guidance to zkEVM development teams.

The performance sprint is over. The era of foundational strengthening has begun, promising a more secure, resilient, and trustworthy Ethereum ecosystem for all. This concerted effort underscores the Foundation’s unwavering commitment to the long-term integrity and success of the Ethereum network, ensuring that innovation proceeds hand-in-hand with uncompromising security.