Stellar Protocol 25 X-Ray, voting tomorrow, introduces native zero-knowledge proof verification capabilities to Stellar smart contracts, including support for BN254 elliptic curves, Poseidon hashing, and Noir circuit verification.
Protocol 25 X-Ray represents a fundamental expansion of Stellar smart contract capabilities by adding native cryptographic primitives for zero-knowledge proofs. The upgrade introduces support for BN254, a pairing-friendly elliptic curve essential to modern ZK systems like Groth16 zkSNARKs and Noir, along with Poseidon and Poseidon2 hashing algorithms optimized for circuit computation. This enables Stellar contracts to verify Noir circuits directly, supporting privacy-preserving applications like private price comparisons and selective disclosure. The upgrade also opens integration with RISC Zero, allowing developers to verify proofs of arbitrary Rust programs executed in a zkVM, enabling complex off-chain computation with on-chain verification. These primitives move zero-knowledge from theoretical research to a production-ready tool in Stellar's developer toolkit.