ZKsync says it has built the first Ethereum prover that can generate proofs in real time on a single GPU. Ethereum co-founder Vitalik Buterin responded two days later with praise, and with homework.
The system is called Airbender Prime, and ZKsync announced it on October 13, 2026. Buterin publicly commended the team on October 15, 2026. He also argued that the focus should now move toward verifying zkEVM security, including system correctness and limits on how much proving can cost.
What Airbender Prime actually did
ZKsync’s headline numbers come from a single NVIDIA RTX PRO 6000 Blackwell GPU. Across 7,200 Ethereum mainnet blocks, Airbender Prime proved 99% in under 10 seconds. Every block in the set was proved within 12 seconds.
The result places Airbender at the top of the ETHproofs.org public leaderboard, where it leads on proving time, GPU efficiency and cost-effectiveness.
A prior iteration of Airbender posted 21.8 MHz of throughput on an H100 GPU. The new version moves the conversation from raw throughput figures to something more tangible: keeping up with live Ethereum blocks on hardware you could plausibly buy.
Under the hood, Airbender relies on hash-based STARKs, a family of proof systems that ZKsync describes as secure against quantum attacks. It is built on RISC-V, an open instruction set standard, and its components are open source.
Buterin’s verdict: speed is solved, safety is next
Buterin did not hedge on the performance side. He framed the race to make proving fast as effectively over.
“Speed battle… definitively won”
Then he pivoted. According to his comments, the next priority should be formal verification that the prover faithfully matches Ethereum’s specifications. He also called for bounds on prover costs tied to gas fees.
How Airbender fits into ZKsync’s roadmap
Airbender is not arriving in isolation. It follows ZKsync’s earlier Atlas upgrade, part of a broader push to expand what Ethereum can handle.
The prover is already running across ZKsync’s supported chains. It was designed to operate efficiently on commodity hardware, with both institutional operators and independent participants in mind.
What this means for Ethereum and its scaling race
On trust, Buterin’s comments effectively reset the scoreboard. The things to watch from here are fairly clear: progress on formal verification of Airbender against Ethereum’s specifications, any published work on prover cost bounds relative to gas, and whether rival zkEVM teams close the gap on the ETHproofs.org rankings.
Disclosure: This article was edited by Estefano Gomez. For more information on how we create and review content, see our Editorial Policy.