The Stellar network is introducing the X-Ray protocol upgrade, which adds native support for BN254 elliptic curve operations and Poseidon hash functions to enable developers to build zero-knowledge privacy applications. The upgrade, scheduled for testnet vote on January 7, 2026 and mainnet vote on January 22, 2026, establishes cryptographic foundations for privacy-preserving applications without compromising Stellar's transparency.
Stellar Development Foundation announced the X-Ray protocol upgrade, a major milestone in the network's long-term privacy strategy outlined at Meridian 2025. The upgrade introduces two critical cryptographic primitives: BN254, a widely-used pairing-friendly elliptic curve, and Poseidon/Poseidon2 hash functions designed for zero-knowledge proof systems. CAP-0074 adds three host functions for BN254 operations (bn254_g1_add, bn254_g1_mul, bn254_multi_pairing_check) that enable efficient zk-SNARK verification and provide feature parity with Ethereum's precompiles, allowing developers to easily migrate ZK applications from EVM environments. CAP-0075 exposes Poseidon permutation primitives to enable ZK-friendly hashing with fewer constraints and lower costs. Together, these capabilities unlock smooth migration of existing ZK applications, more efficient proof systems, and a bridge to the broader ZK ecosystem. Testnet voting begins January 7, 2026, with mainnet voting on January 22, 2026.
