Stellar Hacks: Real-World ZK
This hackathon is wide open: build anything you want with zero-knowledge on Stellar. Privacy pools, private payments, confidential tokens, identity and compliance proofs, provable computation, verifiable data — if it uses ZK and runs on Stellar, it counts. You can go anywhere on the spectrum from mild (a clean proof-of-concept verifier) to wild (a full shielded payment app).
About
Stellar is best known for moving real money in the real world — stablecoins, cross-border payments, tokenized real-world assets, and institutional settlement. So projects that bring ZK to those kinds of real-world use cases are a natural fit and especially welcome. But that's a suggestion, not a requirement. A clever ZK demo, a niche privacy tool, or an experiment that just makes you curious is equally valid as long as ZK is doing real work in it (not just namechecked in the README). We're running this now because Stellar has spent the last few protocol releases building out the cryptographic foundation that modern ZK systems need. Protocol 25 ("X-Ray") introduced native host functions for ZK-friendly primitives — BN254 elliptic-curve operations and Poseidon/Poseidon2 hashing — and Protocol 26 ("Yardstick") built on that with nine additional BN254 host functions (multi-scalar multiplication, scalar-field arithmetic, and curve-membership checks), moving heavy ZK math into the host layer and making proof verification — including NoirLang proofs — meaningfully cheaper to run on-chain. Combined with BLS12-381 from earlier protocols, Stellar now has the on-chain building blocks to verify zk-SNARK proofs efficiently and affordably. A note worth setting expectations on: these primitives are building blocks. They don't, by themselves, give you end-to-end private payments out of the box — you generate proofs off-chain with a higher-level system (Noir, Circom, a RISC Zero zkVM program, etc.) and deploy a verifier contract on Stellar to check them. That gap between "powerful primitives" and "finished product" is exactly where the interesting hackathon projects live. The Resources tab has everything you need to close it.