JOLT
VM Parameters
| Parameter | Value |
|---|---|
| Architecture | Register (RISC-V RV32I) |
| Field | BN254 scalar field 254-bit |
| Field bits | 254 |
| Hash function | Poseidon2 |
| Digest width | 1 field element |
| Extension field | None |
| Stack depth | 32 GP registers |
| Output format | ELF (RISC-V) |
| Cost model | Cycles |
Sumcheck-based SNARK zkVM from a16z. Fundamentally different proof system from STARK-based VMs (SP1, RISCZERO): uses multivariate polynomials and lookup tables ("Just One Lookup Table") with the sum-check protocol.
2x faster than RISCZERO/SP1 in some benchmarks. Twist and Shout memory checking achieves 6x speedup. Highly extensible via "Inlines" — custom operations added without full precompile overhead.
Standard RISC-V RV32I instruction set. Shares RiscVLowering with SP1,
OPENVM, RISCZERO, CKB, POLKAVM, and RISCV.
OS
No dedicated OS. Jolt is a general-purpose proving backend. Proofs can verify on Ethereum or any chain with a suitable verifier contract.
Cost Model (Cycles)
Single metric: cycle count. Sumcheck-based proof system means cost characteristics differ from STARK-based VMs.
| Operation class | Cycles | Notes |
|---|---|---|
| Arithmetic / logic | 1 | Standard RISC-V RV32I |
| Memory access | 1 | Twist and Shout checking |
| Branch | 1 | Conditional and unconditional |
| Inlines (custom ops) | 1 | Extensible via lookup tables |
No dedicated hash coprocessor — all computation is uniform cost. Detailed cost model planned.