Zcash Plans to Introduce Post-Quantum Signatures Next Year
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
ABAB AI Insight
Zcash has separated privacy and transparency into two accounts since its launch in 2016. The Electric Coin Company and Zcash Foundation have long shared control over the protocol and funding. After ECC announced self-funding in 2020, node implementations are no longer limited to one entity. Zakura, this time writing the engineering post as a full node from Valar Group and Project Tachyon, has set the January target for the transparent pool, following the sequence of first modifying the spending exposure and then the shielded circuit. The Sapling and Orchard upgrades both prioritized upgrading the proofs for the shielded pool, while the transparent pool has always been closer to Bitcoin's publicly unspent outputs.
Capital has not flowed into new mining machines or custody orders but rather into the backup layer for signatures. Approximately 11.96 million ZEC, accounting for about 70.4% of the issued amount, is the stock that this round of opcodes aims to cover. Public keys are only revealed upon spending, so the risks for unspent and spent addresses are different. The private queries in Vizor address another issue: wallets expose address sets to the server to monitor rotating addresses. Private information retrieval hides the queries without changing where the coins are in which pool.
In comparison, Quantum Resistant Ledger has used hash signatures since its inception, and Bitcoin developers have discussed post-quantum migration as a multi-year soft fork. Zcash is currently in the preparatory stage for replacement: the opcode is planned to enter the code in January, with mainnet activation undetermined, and the shielded pool will wait for Epoch's production-level goals by the end of 2027. Control lies with the teams writing nodes and submitting opcodes, not with addresses that have already spent their public keys on-chain.
Essentially, this is a technical substitution. The security of elliptic curve signatures relies on the difficulty of deriving the private key from the public key, while hash signatures shift the difficulty to the hash function. The mechanism is about the exposure timing: transparent addresses only publicly disclose hashes before spending, revealing the public key afterward. The decision to first add opcodes to the transparent pool is because this 70% stock is similar to Bitcoin; the zero-knowledge proofs for the shielded pool require circuit changes and cannot be solved with the same instruction. Therefore, the code date appears before the activation date.
ABAB News · Cognitive Law
Public keys are only exposed upon spending; the risks for unspent addresses differ.
The code date is not the activation date.
The 70% stock determines which signature set to modify first.