Hook: The $100M Illusion
Last week, I sat in a Dublin coffee shop with a lead engineer from a freshly announced ZK rollup project that just closed a $100M Series B. The enthusiasm was electric. The founder spoke of scaling Ethereum to Visa-level throughput, of zero-knowledge proofs enabling private, instant transactions. But when I asked the engineer about their actual proving costs under current gas prices, the energy shifted. He pulled out a spreadsheet. The numbers were sobering: at Ethereum’s current base fee of 25 gwei, their monthly proving bill was approaching $2 million. “We’re bleeding cash,” he admitted. “We’re betting on gas dropping back to 5 gwei, but that’s not happening in this bull cycle.”
This is the uncomfortable truth that the ZK narrative conveniently glosses over. The bull market has brought euphoria, massive capital inflows, and a chorus of “ZK is the endgame.” But behind the marketing, a structural flaw is quietly draining the lifeblood of these protocols. The code is open, but the vision is ours to build — and we must build on a foundation that doesn’t bankrupt its operators.
Context: The ZK Proving Cost Crisis
Zero-knowledge rollups (ZK-rollups) are often hailed as the holy grail of Ethereum scaling. They batch thousands of transactions off-chain, generate a succinct proof, and submit that proof on-chain. The promise is lower fees and higher throughput without sacrificing security. But the economics of generating those proofs — the “proving cost” — is a hidden tax that few projects fully disclose.
To understand the scale, we need to look at the two main components: the on-chain verification cost and the off-chain proving cost. The on-chain verification is a fixed gas cost per proof — typically around 300,000 to 500,000 gas for a single ZK-SNARK (depending on the circuit). At 25 gwei, that’s roughly $10–$15 per proof. But the real killer is the off-chain proving cost: the computational resources required to generate the proof itself. A single ZK proof for a batch of 1,000 transactions can require hours of GPU time, costing hundreds of dollars in cloud compute, even before factoring in electricity and hardware depreciation.
Most projects are opaque about these numbers. They tout transaction fees that are a fraction of a cent, but those fees are subsidized by venture capital or by the project’s own token treasury. The moment the subsidy stops — or when gas spikes during a bull market — the math breaks. Volatility is the tax we pay for freedom, but this tax is being levied on the builders, not the users.
During my 2020 DeFi Summer analysis, I built three yield-farming dashboards to understand the cost structures of various protocols. I learned that sustainable protocols have a clear line between operational costs and revenue. ZK rollups, in their current state, lack that clarity. The proving cost is a variable expense that scales with network activity, but transaction fees are often fixed or even zero. This is a recipe for disaster.
Core: The Technical Breakdown of Proving Inefficiency
Let’s dive into the numbers. I’ll use a simplified model based on real-world data from two leading ZK rollups: zkSync Era and Scroll. Both use different proving systems, but the core economics are similar.
For a typical ZK-SNARK circuit (like Groth16), the proof generation involves polynomial commitment, elliptic curve operations, and multi-exponentiations. A single proof for a batch of 1,000 ERC-20 transfers takes approximately 2–5 minutes on a high-end GPU (e.g., NVIDIA A100) and costs roughly $0.50–$1.00 in cloud compute. That doesn’t include the cost of the on-chain verification, which adds another $10–$15. So total cost per batch: $10.50–$16.00. If the batch contains 1,000 transactions, the cost per transaction is $0.01–$0.016. That seems low. But wait — the issue is that the proving cost doesn’t scale linearly with the number of transactions. It scales with the size and complexity of the circuit. A more complex transaction (e.g., a swap with multiple token transfers) can require a larger circuit, increasing proving time and cost by 10x–20x.
Now consider the bull market: gas prices are high, and transaction volume is high. The on-chain verification cost is directly tied to Ethereum gas. At 100 gwei, the verification cost per batch jumps to $40–$60. That’s $0.04–$0.06 per transaction. Meanwhile, the off-chain proving cost also increases because the sequencer must process more transactions, leading to longer queues and higher GPU utilization. The project’s operational costs soar, but the transaction fees they charge users are often capped at a few cents, or even zero to attract users. The result: the project subsidizes every transaction, burning through its treasury.
I recall during my 2022 bear market analysis, I wrote a report titled “The Case for Neutral Infrastructure.” In it, I argued that protocols must be designed to withstand stress, not just thrive in boom times. ZK rollups are currently optimized for a bullish environment (low gas, high volume) but fail spectacularly when gas spikes. The structural integrity of the system is compromised.
Technical Deep Dive: Proving Systems Comparison
Let’s compare two common proving systems: Groth16 and PLONK. Groth16 requires a trusted setup per circuit, but its proof size is small (around 200 bytes) and verification is fast. PLONK eliminates the trusted setup but has larger proofs (around 1KB) and higher verification costs. Most projects use PLONK or its variants (e.g., Halo2) because of the flexibility. But the trade-off is higher on-chain gas costs.
Based on my audit experience (I’ve reviewed three ZK rollup implementations), the verification cost for a PLONK proof is about 500,000 gas, compared to 300,000 for Groth16. At 100 gwei, that’s an extra $10 per batch. Multiplied over thousands of batches per day, that’s an additional $10,000–$20,000 daily. Some projects try to mitigate this by using recursive proofs or aggregators, but those add complexity and latency.
Another hidden cost is the storage of verification keys. Many projects hardcode the keys into the smart contract, but that increases deployment gas costs and is inflexible. A more dynamic approach using on-chain state updates can be expensive. I’ve seen projects spend $50,000–$100,000 just to deploy a ZK rollup contract on Ethereum.
Market Context: The Bull Market Amplifies the Problem
We are currently in a bull market. Ethereum gas is elevated, and transaction volumes are high. This is exactly when ZK rollups should be demonstrating their value. But instead, they are bleeding cash. The equity funding they raised at high valuations is being burned to subsidize user fees. The moment the market turns — or when the next wave of Layer 1 competitors (like Solana or Aptos) offer lower fees without the proving overhead — the ZK rollup narrative will crack.
I see this as a direct parallel to the 2017 ICO era. Back then, I analyzed over 50 whitepapers and found that most projects lacked a sustainable value proposition. They were betting on future adoption that never materialized. Today, ZK rollups are betting on future gas reductions or technological breakthroughs that may not arrive in time. The code is open, but the vision is ours to build — and we must build with honest economics.
Contrarian Angle: The “Efficiency Myth”
Here’s the contrarian thought: maybe ZK rollups are not the optimal scaling solution for a bull market. Perhaps the industry’s fixation on “ZK” is blinding us to simpler, cheaper alternatives like optimistic rollups or even sidechains. Optimistic rollups (like Arbitrum or Optimism) have lower proving costs — they don’t generate proofs; they rely on fraud proofs. The on-chain cost is just a simple state root submission, which is far cheaper. The trade-off is a 7-day withdrawal delay, but that’s a UX problem, not a cost problem.
I’ve been a vocal advocate of decentralization, but I also believe in economic pragmatism. If a ZK rollup is spending $1 million per month on proving costs while only generating $200,000 in fees, it’s not sustainable. It’s a protocol that relies on continued venture capital injection. We do not follow trends; we architect ecosystems. And ecosystems must be self-sustaining.
Another blind spot is the centralization of proving. Many ZK rollups use a single sequencer to generate proofs. This is a trust assumption. If the sequencer goes down or is malicious, the entire network stops. Decentralized proving is still in its infancy. The cost of a decentralized prover network would be even higher. So the current model is a centralized solution that is expensive — the worst of both worlds.
The Institutional Perspective
Since 2024, I’ve been bridging the gap between crypto and traditional finance. I’ve explained to CFOs and risk managers that blockchain is not just a speculative asset, but a new infrastructure. They ask me: “What are the operational costs of these protocols?” When I show them the proving cost breakdown, they are shocked. They are used to cloud computing costs that are predictable and decreasing. ZK proving costs are volatile and increasing. In a bear market, it might be viable, but in a bull market, it’s a liability.
I’ve created a simple model: if the ratio of on-chain verification cost to transaction fees exceeds 20%, the protocol is not sustainable. Many ZK rollups are operating at 40–60% today. They are only surviving because of token incentives. When the incentives dry up, so will the users.
Takeaway: The Clock is Ticking
So, what does this mean for the future? ZK rollups are not going to die. They are a fascinating technology with profound implications for privacy and scalability. But the current economic model is broken. The industry must either (a) develop cheaper proving systems (e.g., using recursive proofs or hardware accelerators), (b) accept higher transaction fees, or (c) rely on Layer 2 token subsidies.
Option (c) is the most likely in the short term. But it’s a Ponzi-like dynamic: the token’s value relies on the success of the rollup, but the rollup’s success relies on the token’s value. This is fragile. From the ashes of FUD, we forge true adoption. The adoption will come from protocols that are structurally sound, not from those that are propped up by venture capital.
I’ll be watching the next few months closely. If gas stays above 50 gwei, we will see a shakeout. Some ZK rollups will pivot to alternative chains (like Celestia or Avail) to reduce base layer costs. Others will merge. The survivors will be those that prioritize cost efficiency over narrative.
Trust is not given; it is compiled, line by line. And right now, the lines of code for ZK rollups are compiling a cost that is too high. We need to fix the economics before the next bear market hits. Otherwise, we will be left with a pile of proofs and no users. The architect must be honest about the materials.