Roman Akhtariev, an engineer from the Zcash full node program Zakura, wrote in an engineering post that the team plans to incorporate post-quantum signature opcodes into Zcash in January. The goal is to enable the network to verify hash-based signatures for authorizing payments on transparent addresses. The post did not provide a mainnet activation date; January is the target for code implementation, not a confirmed activation time.

This round of arrangements prioritizes transparent addresses. Initially, transparent addresses only publicly disclose the public key hash, revealing the public key only when spending. Zakura's plan is to pair a hash signature as a backup alongside the existing elliptic curve keys, constructing a reference WOTS, corresponding to the Internet Engineering Task Force document RFC 8391. A complete post-quantum secure transparent pool is also set as a January target. Shielded addresses use zero-knowledge proofs to hide the sender, receiver, and amount, requiring a different layer of protection, which is not included in this round of opcodes.

According to CoinDesk's calculations based on ZecStats, as of Thursday, approximately 11.96 million ZEC are in the transparent pool, with about 16.98 million issued, roughly 70%. TokenPost provided more detailed data as of 5:39 AM Eastern Time on October 9: there are 11,958,838 transparent unspent outputs, with 16,976,561 issued, accounting for 70.4%. Transparent transactions disclose addresses and amounts, while shielded transactions hide the sender, receiver, and amount.

Zakura has also developed a private information retrieval tool that allows wallets to check balances and history by address without sending the queried address list to the server. Confirmed transparent activities are partitioned by block intervals, with the wallet first verifying filters locally and then making private queries only for potentially matching intervals. The experimental switch has been placed in the Private queries settings of the Zcash wallet Vizor. Zakura is built by Valar Group and Project Tachyon.

Ethereum researcher Justin Drake called on the industry on October 7 to prepare for Bunker Mode, transferring funds to new addresses that have never been signed, stating that in the worst-case scenario, existing signatures could expire in months rather than years. There have been no confirmed practical quantum attacks against mainstream wallet keys in public records. Another more comprehensive post-quantum route is being advanced by Shielded Labs' Epoch, which publicly reports its production-level cryptographic goals set for the end of 2027.

This is not a spot trading announcement but a timeline for the signature scheme replacement. Buyers are those who still keep about 70% of ZEC in the transparent pool and are concerned about public key exposure after spending; sellers face pressure as the opcodes have not yet been activated, and wallets have not yet completed the full process for rotating addresses with WOTS. The event is driven by the engineering post and Bunker Mode warnings, not by large on-chain transfers. Beneficiaries are addresses in the transparent pool that have not yet exposed their public keys; those under pressure are transparent outputs that have already spent coins and have their public keys on-chain, as well as shielded pools that still lack independent post-quantum paths.

Incorporating opcodes into the code and network activation are two steps. Before January, the engineering post states that hash signatures can be used with existing keys to create rotating addresses, but there is no integrated wallet process yet.

Source: Public Information