Researchers Publish 'Zcash-Style' Design for Private Bitcoin Transfers
Researchers at [[alloc] init] published a 56-page design for “Shielded Bitcoin,” a Zcash-style privacy system that would hide sender, recipient, and amount while using the existing Bitcoin network. The scheme stores value as encrypted notes and uses zero-knowledge proofs to show that inputs are valid and outputs balance, while a public nullifier prevents double-spends without revealing which note was spent. Unlike Zcash’s own blockchain, Bitcoin would only carry the transfer data; separate indexers would verify proofs and reconstruct shielded state. The design preserves privacy of who paid whom and how much, but not that a shielded transfer occurred. Timing, fees, and input/output counts remain public. The current version uses Groth16, so it depends on a trusted setup ceremony, and it publishes transfers via OP_RETURN. Entry into and exit from the shielded system are left to a separate proposal built on PIPEs v2.
