Definition: RISC Zero is a zero-knowledge virtual machine (zkVM) that proves the correct execution of a supported Rust guest program compiled to a RISC-V ELF binary. Its receipt lets another party verify the program and its committed public outputs without re-running the whole computation.
Guest program, image ID, and receipt
A host prepares the guest program and its input, the executor records a session, and the prover produces a receipt. The receipt binds the execution claim to the program’s image ID; a verifier checks that receipt. The journal contains outputs the guest deliberately commits as public, so developers must decide carefully which results belong there.
Proof system and Ethereum
RISC Zero’s proof system uses STARK techniques, with optional wrapping for applications that need a smaller or cheaper on-chain verification path. Its Ethereum documentation describes using a zkVM as a coprocessor for computation that would be costly or cumbersome in a smart contract. The proof establishes the specified computation, not that the application’s inputs, code, or assumptions are sensible.
Local and remote proving
Proof generation can use local resources or a remote proving workflow. Current developer documentation presents remote proving through Boundless. A zero-knowledge proof protects private witness data from a verifier when the protocol is used as designed; it does not hide plaintext inputs from the host or remote proving service that must process them. Consider provider trust and the data sent for a job.
Social Media Sentiment
A 2026 r/ethereum discussion argued that remote prover networks can receive plaintext inputs and questioned how that affects applications that expect privacy. Replies distinguished private user data from rollup workloads whose inputs are already public. This is one discussion and a design concern, not proof that every RISC Zero deployment exposes user data. Read the referenced Reddit discussion.
Last updated: 2026-10
Related Terms
See Also
- What Are Zero-Knowledge Proofs?
- Are Layer 2 Networks Decentralized?
- Why Smart Contract Audits Fail
- Swap crypto with ChangeNOW
Sources
- RISC Zero Developer Docs: zkVM Overview — Documents guest programs, RISC-V ELF execution, the host, prover, session, and receipt workflow.
- RISC Zero Developer Docs: Proof System Overview — Explains receipts, verification, the public journal, and the system’s STARK-based receipt structure.
- RISC Zero Developer Docs: RISC Zero on Ethereum — Describes verifying zkVM results in Ethereum contracts and using the zkVM as a coprocessor.