Flawed incentive structures may compromise the security of Ethereum's Layer-2 solutions, according to a recent study

Researchers from zkSecurity, Prooflab, and Imperial College London have uncovered significant vulnerabilities in the fee structures of Ethereum Layer-2 rollups, cautioning that incorrect pricing of small transactions could introduce systemic threats to the network. Their paper, “Unaligned Incentives: Pricing Attacks Against Blockchain Rollups,” points out that the current models for computation, data availability, and settlement fees are overly basic, which can result in transactions being priced too high or too low. This mispricing opens the door to issues such as excessive costs for users and the risk of denial-of-service (DoS) attacks, where attackers take advantage of underpriced transactions to flood the network with spam at minimal expense Decrypt.co [ 1 ].

Rollups, which aggregate transactions to lower expenses on

, depend on three separate types of resource costs: computation (processing transactions), data availability (recording data on the blockchain), and settlement (submitting proofs to layer-1). The study discovered that most rollups simplify these into a single pricing formula or fixed rule, overlooking the fact that each cost can vary independently. For instance, Polygon zkEVM, Era, Scroll, Optimism, and all use different fee approaches—some set fees at the time of transaction submission, others wait until batches are finalized, and some provide refunds if actual costs are lower than estimated. While these systems appear technical, they create loopholes that can be exploited. For example, a refund mechanism allows malicious actors to submit large numbers of transactions, reclaim part of their fees, and still use up network resources Decrypt.co [ 1 ].

The dangers go beyond mere inconvenience for users. The authors argue that flawed pricing could let attackers subsidize small transactions, potentially flooding the network and degrading service for genuine users. These weaknesses arise not from programming errors, but from economic design flaws that misalign incentives. With Ethereum’s rollup ecosystem now safeguarding assets worth tens of billions, the paper stresses the need to urgently address these issues. “It is no longer safe to ignore these incentive gaps,” the authors state, highlighting that static or flat fee models are especially prone to abuse Decrypt.co [ 1 ].

After analyzing five leading rollups, the researchers found significant differences in how fees are calculated. Some networks adjust fees in real time based on demand, while others stick to fixed rates. Another paper on arXiv, “Optimistic MEV in Ethereum Layer 2s,” sheds further light on the problem, showing that speculative transactions like cyclic arbitrage make up more than half of on-chain gas usage on Base and Optimism. These optimistic MEV transactions, which depend on on-chain smart contracts, generate ongoing spam-like activity, using up half the gas but paying less than a quarter of total fees. The study links this to fee models that don’t reflect the variable costs of zero-knowledge virtual machines (zkVMs) arXiv [ 3 ].

To address these vulnerabilities, the authors recommend adopting “multidimensional” fee structures that separately price computation, data posting, and proof generation. By matching fees to actual resource consumption, they argue, networks can better resist spam and provide users with more predictable costs. Solutions such as dynamic fee adjustments, partial batching, and transparent cost reporting are suggested. Although some rollup projects are testing adaptive fee models and real-time pricing, the study notes that a universal standard has yet to emerge. These findings come as Ethereum continues to focus on rollup-based scaling, with zero-knowledge proofs and zkVMs playing a key role in boosting throughput. However, unless fee variability is properly managed, these models could fail under pressure, resulting in inconsistent user experiences and reduced reliability Decrypt.co [ 1 ].

For both developers and investors, the research highlights the need to look beyond surface-level metrics like throughput or low advertised fees and closely examine how fees are determined. “Incentives are security,” the authors emphasize, calling on the Ethereum community to make transaction pricing a core part of consensus design. As rollups expand, the relationship between fee models, user actions, and network safety will become even more important. The publication of this study comes amid ongoing debates about Ethereum’s economic structure, including criticism of proposals to levy fees on Layer-2s, which some believe could hinder scalability and the growth of the ecosystem CryptoPotato [ 2 ].

This research spotlights a crucial issue for Ethereum’s ongoing development: finding the right balance between user accessibility and network security. While Layer-2 solutions have brought down costs and increased throughput, their fee systems must evolve to prevent abuse. As the ecosystem grows, multidimensional pricing could become the norm, helping rollups stay both efficient and robust against malicious activity. For now, the message is clear—fixing incentive misalignments in fee design is not just a technical tweak, but a vital step toward sustainable blockchain scaling Decrypt.co [ 1 ].