Researchers Design Zcash-Style Private Bitcoin Transactions, Indonesia's Crypto Regulation at Stake

A team of Bitcoin cryptography developers has published a Zcash-style private transfer design that it claims can hide the identity of senders, recipients, and transaction amounts on top of the existing Bitcoin network. The 56-page paper dated 24 September 2026 was written by Clara Shikhelman, Mikhail Komarov, and Aleksei Moskvin, as cited from Yahoo Tech.

The design, called Shielded Bitcoin, offers advanced privacy without the need for a fork or changes to Bitcoin's consensus rules. Value is stored in the form of encrypted 'notes', and each transfer carries a zero-knowledge proof that verifies ownership and the balance of inputs and outputs. A public marker called a nullifier allows the software to reject double-spending without revealing which note was used.

Unlike Zcash, which enforces its rules through its own blockchain, Shielded Bitcoin publishes transfers as data on Bitcoin. The Bitcoin network only records without checking, while a separate software called an indexer verifies the proofs and rebuilds the shielded state. This approach is claimed to be more practical because it does not burden Bitcoin nodes with additional validation.

Despite offering anonymity, the authors acknowledge that transaction timing, fees, and the number of inputs and outputs remain publicly visible. 'Like Zcash and Monero, Shielded Bitcoin protects who pays whom and how much, not the fact that a shielded transfer occurred,' they wrote in the paper. This limitation is an important note for regulators who have so far relied on transaction trails for audits.

"We have been working on this for a long time," said Scott Odell, COO of the Bitcoin cryptography developers, via a post. He described the contribution as an effort to make Bitcoin 'private, without changing Bitcoin'.

The paper also highlights the difference from the 2025 Shielded CSV proposal, which requires coin owners to store transaction data themselves. Shielded Bitcoin relies on an indexer to recover data from the chain, making it more user-friendly. However, the reliance on the larger default OP_RETURN in Bitcoin Core v30 is a weak point because the change is controversial and can be reversed by node operators.

An appendix in the paper discusses an optional compliance layer. In it, a 'Trust Authority' can certify approved deposits, allowing institutions to verify the origin of a note without exposing the transfer graph. Notes without such proof remain valid, raising questions about how far compliance can be enforced.

For Indonesia, this development is a test for the crypto asset regulatory framework currently being built. The Financial Services Authority (OJK) and Bappebti have so far emphasized the importance of transaction transparency for preventing money laundering and terrorism financing. The presence of privacy features like Shielded Bitcoin could complicate the tracking of fund flows, especially if adopted by local exchanges. On the other hand, domestic industry players may see it as an opportunity to improve service competitiveness, provided there is an agreed audit mechanism.

Zcash itself is now traded through regulated funds in the United States and Europe. Grayscale launched a Zcash ETF on NYSE Arca on 25 August, followed by 21Shares listing a similar product on Euronext Paris and Amsterdam on 22 September. CoinGecko data shows ZEC at US$1,592 on 25 September, up 4% in a day with a seven-day high of US$1,658.86.

Going forward, the adoption of Shielded Bitcoin will depend on support from nodes and miners to maintain the OP_RETURN policy. If successful, it could change the privacy landscape on the Bitcoin network—while forcing regulators in various jurisdictions, including Indonesia, to reconsider the balance between innovation and oversight. Will privacy become a standard feature, or will it instead trigger a wave of tighter rules?