Over the past 90 days, I have audited the constraint systems of four major ZK-rollup projects. Three of them have reduced verification costs by more than 20% since Q1. All three did it by pruning constraint gates that their teams deemed "redundant." None of them published the full diff. Code does not lie, but it often omits the context.
This is not a theoretical concern. In the current bear market, every L2 team is under pressure to show lower gas fees, faster finality, and leaner operating costs. The easiest way to achieve all three is to shrink the proof system. The hardest way is to optimize the circuit design without sacrificing security margins. Most teams are choosing the easy path. I have seen the diffs. I have traced the constraint deletions. The pattern is consistent, and it is dangerous.
Let me be precise about what I mean by "pruning constraint gates." A ZK-rollup's proof system is built on a constraint system โ a set of polynomial equations that must hold true for a transaction batch to be valid. Each constraint gate represents a logical check: a signature verification, a state transition rule, a balance conservation law. More gates mean more computation during proof generation and more data during verification. Fewer gates mean lower costs. But fewer gates also mean fewer checks. The question is which checks you remove.
In a healthy protocol, you remove gates that are mathematically redundant โ checks that are implied by other constraints. In an unhealthy protocol, you remove gates that are merely expensive to compute. The distinction is subtle, and it is exactly where the security breakdown occurs.
I have spent the last six months reverse-engineering the verification circuits of several ZK-rollup projects. My background is in data science, but my current work is in zero-knowledge cryptography. I joined a boutique blockchain security firm in 2024, and my primary focus has been optimizing proof generation for a new ZK-rollup. That experience gave me a front-row seat to how teams make cost-cutting decisions under market pressure. What I found is that the bear market is not just squeezing token prices. It is squeezing security margins.
Let me walk through the mechanics. A ZK-rollup batches thousands of transactions into a single proof. That proof is verified on the Ethereum mainnet. The verification cost is paid in gas, and gas is paid in ETH. When ETH prices fall, the dollar cost of verification falls too โ but the protocol's revenue also falls. So the ratio of verification cost to protocol revenue stays roughly constant. Teams feel the squeeze regardless of the ETH price. The pressure to reduce verification costs is structural, not cyclical.
The standard approach to reducing verification costs is to reduce the number of constraint gates. This is done through a process called "circuit optimization." The circuit is the mathematical representation of the transaction logic. Each operation โ a hash, a signature check, a Merkle proof โ is broken down into elementary constraints. The total number of constraints determines the proof size and the verification time. Fewer constraints mean cheaper verification.
There are legitimate ways to reduce constraints. You can use more efficient hash functions. You can batch operations. You can use lookup tables to replace expensive arithmetic with cheaper memory lookups. These are all valid optimizations that preserve security. But there is another category of optimization that is not valid: removing constraints that protect against edge cases.
Here is a concrete example. In one project I audited, the team removed a constraint that checked for overflow in the account balance field. The constraint was expensive because it required a 256-bit multiplication. The team argued that the overflow was "practically impossible" because the maximum balance was bounded by the total token supply. That argument is technically correct for a single transaction. But it fails for a batched transaction. If an attacker can craft a batch where two transactions interact in a way that bypasses the individual balance checks, the overflow becomes exploitable. The team removed the constraint because it was expensive, not because it was redundant. That is the difference between optimization and negligence.
I have seen this pattern repeated across multiple projects. The most common targets for removal are:
- Overflow and underflow checks on arithmetic operations
- Redundancy checks on Merkle proof paths
- Signature malleability checks
- Nonce monotonicity checks
- Cross-transaction state transition invariants
Each of these checks has a cost. Each of them protects against a specific attack vector. And each of them is being removed by teams that are desperate to show lower gas fees in a bear market.
The irony is that the cost savings are marginal. Removing a single constraint gate might reduce verification cost by 0.1%. To achieve a 20% reduction, you need to remove hundreds of gates. That means you are not just trimming fat โ you are cutting into muscle. The probability that you have removed a security-critical constraint is high. The probability that you have introduced a vulnerability is even higher.
Let me quantify this. In my audit of one project, I identified 47 constraint gates that had been removed in the latest upgrade. Of those, 12 were genuinely redundant โ they were implied by other constraints. The remaining 35 were security-critical. They protected against specific attack vectors that I could demonstrate with crafted inputs. The team's response was predictable: "We will add them back in the next upgrade." But the next upgrade is six months away, and the protocol is live with 35 missing security checks.
This is not an isolated incident. I have seen the same pattern in three of the four projects I audited. The fourth project had a more conservative approach โ they only removed constraints that were proven redundant through formal verification. That project's verification cost is 15% higher than its competitors. But its security margin is intact.
The market does not reward security margins. It rewards low fees and fast finality. In a bear market, users are price-sensitive. They will move to the cheapest rollup, even if it is less secure. This creates a race to the bottom. Teams that maintain high security standards are punished by the market. Teams that cut corners are rewarded. This is the fundamental misalignment in the current ZK-rollup ecosystem.
I have been in this industry since 2017. I have seen ICOs with reentrancy vulnerabilities that drained millions. I have seen DeFi protocols with oracle manipulation risks that caused flash crashes. I have seen cross-chain bridges with critical flaws that were dismissed because the team did not take a junior analyst seriously. The pattern is always the same: security is sacrificed for speed, and the market rewards the sacrifice until it does not.
The current ZK-rollup landscape is repeating this pattern. The bear market is accelerating it. Teams are under pressure to show growth, and growth is measured in TVL and transaction volume. Low fees drive growth. Low fees require cheap verification. Cheap verification requires constraint pruning. Constraint pruning introduces vulnerabilities. The vulnerabilities are not immediately exploitable โ they require sophisticated attacks that take time to develop. But they are there, waiting.
Let me give you a specific technical example from my audit work. In one project, the team had removed a constraint that checked the consistency of the public inputs between the proof and the transaction batch. This constraint is critical because it ensures that the proof actually corresponds to the transactions being verified. Without it, an attacker could potentially submit a proof for a different batch of transactions than the one being verified. The team argued that the constraint was redundant because the proof system already binds the public inputs through the commitment scheme. That argument is wrong. The commitment scheme binds the inputs to the proof, but it does not bind the proof to the on-chain transaction data. The constraint was the only thing ensuring that the verified proof matched the submitted batch.
I demonstrated this vulnerability with a crafted proof that verified successfully but corresponded to a different transaction batch. The team was shocked. They had assumed the commitment scheme was sufficient. They had not realized that the constraint was doing additional work. The fix was simple โ add the constraint back โ but the damage was done. The protocol had been live for three months with this vulnerability.
This is the kind of subtlety that gets lost in the cost-cutting process. Teams focus on the big picture โ the overall proof system, the cryptographic assumptions, the protocol design. They do not focus on the individual constraints that protect against edge cases. But security is built on edge cases. An attacker does not need to break the cryptographic assumptions. They just need to find one edge case that was not checked.
My experience in 2020 taught me this lesson. I was working as a junior analyst during the DeFi Summer. I noticed that several lending protocols were using delayed price feeds from oracles. The delay was small โ a few seconds โ but it was enough to create a window for manipulation. I published a technical report detailing how delayed data feeds could lead to undercollateralization. My report was dismissed by most teams. They argued that the delay was negligible and that the protocols had other safeguards. Three weeks later, the August 2020 flash crash hit. Several protocols lost millions due to exactly the vulnerability I had identified. My team avoided the loss because we had already exited our positions. But the lesson stuck with me: security is about the edge cases, not the main path.
The same lesson applies to ZK-rollups today. The main path โ the proof generation, the verification, the state transition โ is well-designed and well-tested. The edge cases โ the overflow conditions, the malleability attacks, the cross-transaction invariants โ are where the vulnerabilities live. And these are exactly the constraints that are being removed in the name of cost optimization.
Let me talk about the economics more precisely. The verification cost of a ZK-rollup is typically 100,000 to 500,000 gas per batch. At current ETH prices, that is roughly $0.50 to $2.50 per batch. If a rollup processes 1,000 batches per day, the daily verification cost is $500 to $2,500. Reducing verification cost by 20% saves $100 to $500 per day. That is $36,000 to $180,000 per year. For a protocol with a $10 million treasury, that is a meaningful saving. But it is not worth the risk of a security breach. A single exploit could drain the entire treasury.
The risk-reward calculation is clear: the savings are bounded, but the potential loss is unbounded. Yet teams continue to cut corners. Why? Because the probability of an exploit is low, and the probability of a cost saving is certain. Teams are rational actors. They optimize for expected value. The expected value of cost cutting is positive if the probability of an exploit is low enough. And the probability of an exploit is low โ until it is not.
This is the fundamental problem with security in the blockchain industry. Security is a probabilistic concept. You cannot prove that a system is secure. You can only prove that it is secure against known attacks. The unknown attacks are the ones that get you. And the more constraints you remove, the more unknown attacks become possible.
I have been advocating for a different approach. Instead of removing constraints, teams should optimize the constraint system itself. This means using more efficient cryptographic primitives, better circuit design, and formal verification tools. These approaches reduce costs without sacrificing security. But they require expertise and time. In a bear market, teams do not have time. They need results now.
The result is a market where the most cost-efficient rollups are also the least secure. This is a market failure. Users are making decisions based on incomplete information. They see low fees and assume the protocol is well-designed. They do not see the missing constraints. They do not see the edge cases that are unprotected. They do not see the security time bomb that is ticking underneath the surface.
Let me give you a framework for evaluating ZK-rollup security. When you look at a rollup's codebase, ask these questions:
- How many constraint gates are in the circuit? A healthy circuit has a high gate count. A circuit that has been aggressively pruned will have a lower count.
- What is the ratio of security-critical constraints to total constraints? This is hard to measure without a full audit, but you can look for signs of pruning.
- Has the team published a full diff of their circuit changes? If not, they are hiding something.
- Does the team use formal verification tools? If not, they are relying on manual review, which is error-prone.
- What is the team's security budget? A team that spends less than 10% of its budget on security is a red flag.
These questions are not exhaustive, but they give you a starting point. The key insight is that security is not a binary property. It is a spectrum. And the spectrum is shifting in the wrong direction.
I want to be clear about my own biases. I am a security researcher. I make my living by finding vulnerabilities. I have a financial incentive to be pessimistic about security. But my pessimism is based on data, not on incentives. I have audited the code. I have traced the constraint deletions. I have demonstrated the exploits. The data is clear: ZK-rollup security is deteriorating.
The contrarian angle here is that the market is rewarding the wrong behavior. Low fees are celebrated. High security is ignored. This is backwards. In a bear market, the protocols that survive are the ones with the strongest security, not the lowest fees. The protocols that cut corners will be the ones that fail when the next exploit hits.
I have seen this movie before. In 2017, I audited ICO smart contracts. I found reentrancy vulnerabilities in two of the three projects I examined. I submitted pull requests to their GitHub repositories. One project accepted my fix. The other dismissed it. The first project survived the 2018 bear market. The second project was drained by an attacker in early 2018. The difference was not the quality of the team or the strength of the tokenomics. It was the willingness to accept security fixes.
The same pattern is playing out today. The ZK-rollup projects that are willing to invest in security will survive. The ones that are cutting corners will not. The question is which ones are which. And the answer is not visible from the outside. You have to look at the code.
Let me give you a practical example of what to look for. In one project I audited, the team had replaced the standard Poseidon hash function with a custom hash function that was 30% faster. The custom hash had not been peer-reviewed. It had not been formally verified. It was simply faster. The team argued that the speed improvement was worth the risk. I argued that the risk was unacceptable. The team went ahead with the custom hash anyway. Six months later, a researcher found a collision in the custom hash. The team had to issue an emergency upgrade. The upgrade cost them more in downtime and lost trust than they had saved in gas fees.
This is the pattern. Short-term optimization leads to long-term costs. The market rewards the short-term optimization. The long-term costs are borne by the users. And when the costs materialize, the team blames the attacker, not their own cost-cutting.
I am not saying that all ZK-rollup teams are cutting corners. There are teams that are doing it right. They are investing in formal verification. They are publishing their circuit diffs. They are maintaining high security standards. But these teams are in the minority. And they are being punished by the market for their prudence.
The takeaway is not that ZK-rollups are fundamentally broken. The takeaway is that the current incentive structure is broken. Teams are rewarded for cutting costs, not for maintaining security. This is a fixable problem. We need better auditing standards. We need mandatory circuit diff publication. We need formal verification requirements. We need the market to reward security, not just low fees.
But these changes will not happen overnight. In the meantime, users need to be vigilant. They need to look at the code. They need to ask the hard questions. They need to understand that low fees are not a sign of security. They are often a sign of the opposite.
I have been in this industry for 14 years. I have seen multiple bear markets. I have seen multiple security crises. The pattern is always the same. The market rewards risk-taking until the risk materializes. Then the market punishes everyone. The only way to avoid being punished is to be on the right side of the risk. And the right side of the risk is the side that maintains security.
In the next 12 months, I expect to see at least one major ZK-rollup exploit. It will be caused by a constraint that was removed in the name of cost optimization. The exploit will drain millions. The team will blame the attacker. The market will lose confidence in ZK-rollups. And the teams that maintained high security standards will be vindicated. But the damage will already be done.
The question is not whether this will happen. The question is whether you will be on the right side of it. Will you be using a rollup that has maintained its security margins? Or will you be using a rollup that has cut corners to save a few dollars in gas fees? The choice is yours. But the data is clear. Code does not lie, but it often omits the context. And the context is that ZK-rollup security is deteriorating, and the market is rewarding the deterioration.
I have spent the last six months auditing these systems. I have seen the constraint deletions. I have traced the security gaps. I have demonstrated the exploits. The evidence is overwhelming. The ZK-rollup ecosystem is building on a foundation of sand. The sand is being eroded by cost-cutting. And when the foundation collapses, the collapse will be sudden and catastrophic.
This is not a prediction. It is a probability assessment. The probability of a major ZK-rollup exploit in the next 12 months is high. The probability that it will be caused by constraint pruning is even higher. The probability that the team will have ignored warnings from security researchers is almost certain. I have seen the warnings. I have issued them myself. And I have been ignored.
But I will keep issuing warnings. I will keep auditing the code. I will keep publishing my findings. Because that is what I do. I am a security researcher. I find vulnerabilities. I report them. And I hope that someone listens before it is too late.
The bear market reveals the skeleton. The skeleton of the ZK-rollup ecosystem is showing cracks. The cracks are getting wider. And the collapse is coming. The only question is when.
Trust no one. Verify everything. And when you verify, look at the constraints. Look at what has been removed. Look at what is missing. Because what is missing is what will kill you.
