Stellar developers discussed CAP74, which adds BN254 pairing-friendly curve support to Soroban via three new host functions, and explored approaches for implementing Poseidon hash functions to support zero-knowledge proof use cases on the network.
The meeting covered two major protocol enhancement proposals for Stellar. First, CAP74 introduces host functions for the BN254 pairing-friendly curve (g1add, g1mult, pairing check) to support existing ecosystem use cases that rely on BN254, achieving parity with EVM precompiles. Second, developers discussed three approaches for adding Poseidon hash function support to Soroban: hardcoded implementations per curve and arity, exposing sponge building blocks for flexibility, or implementing entirely in WASM. Testing showed WASM implementation requires 17.6 million instructions per hash, making native host support preferable. The team favored approach two, exposing configurable building blocks with standard parameters, balancing performance, protocol complexity, and interoperability with existing proving frameworks like Circom.