Researchers propose Zcash-style private Bitcoin transfers without a soft fork
Researchers at Alloc Init proposed “Shielded Bitcoin,” a way to add Zcash-like private transfers to Bitcoin without a soft fork. The system would hide amounts, senders, receivers, and spending links using encrypted notes and zero-knowledge proofs. Bitcoin would act only as a neutral layer for publishing and ordering transactions, while separate indexers would verify proofs, prevent double-spends, and maintain the shielded state. The design borrows heavily from Zcash: encrypted notes, public nullifiers, and validity proofs, but it would not need its own blockchain or consensus. Reactions were mixed. Some critics said it offers little new beyond Zcash and would begin with no anonymity set, reducing privacy at launch. The researchers agreed privacy depends on a large crowd and noted patterns can still leak relationships. Others questioned its lack of post-quantum security. Eli Ben-Sasson was more supportive, saying the original Zerocash vision was to bring privacy to Bitcoin.
