4. General-Purpose zkVMs: Succinct SP1 & Validity Rollups

The Shift from DSLs to General-Purpose zkVMs

Writing custom circuits in Circom is labor-intensive and difficult to audit. General-purpose zero-knowledge virtual machines (zkVMs) implement an open CPU instruction set architecture—most notably RISC-V—as an arithmetic constraint system. Developers write standard Rust, compile to a RISC-V ELF binary, and prove execution without writing custom cryptographic gates.

Succinct SP1 Architecture & Performance

Succinct SP1 is a high-performance open-source zkVM optimized for rollups, coprocessors, and verifiable compute. It introduces modular precompiles for costly cryptographic operations (keccak256, sha256, secp256k1 signature recovery, ed25519) and utilizes Plonky3 to achieve industry-leading proof generation speeds.

// Conceptual Succinct SP1 Rust Guest Program
// #![no_main]
// sp1_zkvm::entrypoint!(main);
//
// pub fn main() {
//     let n = sp1_zkvm::io::read::<u32>();
//     let mut a = 0u64;
//     let mut b = 1u64;
//     for _ in 0..n {
//         let c = a + b;
//         a = b;
//         b = c;
//     }
//     sp1_zkvm::io::commit(&a);
// }

Recursive Proving & Ethereum L1 Verification

Proving large execution traces generates extensive intermediate state. Succinct SP1 uses recursive STARK-to-SNARK wrapping: the internal fast STARK proof is recursively reduced into a single Groth16 or Plonk proof that can be verified on Ethereum L1 for ~250,000 gas.