Crypto glossary
zkVM
A zkVM is a virtual machine that generates a zero-knowledge proof that a program ran correctly, so developers can prove ordinary code, not custom circuits.
Early zero-knowledge applications required developers to express their logic as arithmetic circuits, a slow, specialised task. A zkVM removes that barrier. It emulates a general instruction set, most commonly RISC-V, so developers write programs in languages like Rust, compile them as usual, run them inside the zkVM and receive a proof that the execution produced a given output. Anyone can verify the proof cheaply.
zkVMs have become core infrastructure. They power zk rollups and validity proofs for other chains, trust-minimised bridges that prove the consensus of one chain on another, coprocessors that compute over historical data, and proofs of entire Ethereum blocks. In 2025 several teams showed they could prove most Ethereum blocks within the 12-second slot using large GPU clusters, fuelling plans to use such proofs on Ethereum's base layer.
Proving is still far more expensive than running the program normally, often requiring specialised hardware or proving markets. Complex systems also carry bug risk: a flaw in the zkVM or its proof system could let invalid executions be accepted, so audits, formal verification and multiple independent provers are important safeguards.
Example
A bridge runs a light client of another blockchain as a Rust program inside a zkVM and posts the resulting proof to Ethereum, where a contract verifies it before releasing deposited funds.