Zcash quantum-resistant signatures are due as soon as January: what they will protect and what they won't

What the developers announced

Zakura is an alternative Zcash full node program built by Valar Group and Project Tachyon, and its first release came out in July 2026. In an engineering note, its developer Roman Akhtariev wrote: “Our team plans for post-quantum signature opcodes to land in Zcash in January.”

An opcode is an instruction the network follows to verify the signature on a payment. The new instructions will make it possible to verify hash-based signatures. Today's Zcash signatures, like those of bitcoin and ether, rely on elliptic curves: a powerful enough quantum computer could, in theory, compute the private key from the public one. Hash-based signatures rest on different mathematics, so breaking today's keys does not affect them. The options the developers are considering include Winternitz One-Time Signatures (WOTS).

An important caveat: January is a development target. There is no mainnet activation date, no final specification and no schedule for a mandatory migration yet.

The statement came during a nervous week. Ethereum Foundation researcher Justin Drake called for preparing “bunker mode”, a move of coins to fresh addresses, and warned that in the worst case a weakness in today's signatures could be found with the help of AI in “months, not years”. No one has demonstrated a practical attack on wallet keys, but after his post ZEC fell harder than other large coins: it ended Thursday at about $1,185, down roughly 11% over the week. We covered the call itself in our article on what “bunker mode” is and whether you should move your coins.

Why transparent addresses come first

Zcash is known as a privacy coin, but most ZEC sits in plain view. According to ZecStats data as of October 8, about 11.96 million of the roughly 16.98 million ZEC issued are in the transparent pool. That is 70.4%. The shielded pools hold about 4.95 million.

Zcash transparent addresses work like bitcoin's: addresses and amounts are visible to everyone. They share the same weakness too. While you are only receiving coins, the public key stays hidden behind the hash of the address. Once you send from the address, the key lands on the blockchain and stays there forever. The public key is exactly what a quantum attack needs.

So the logic of the first stage is simple: protect the part that holds the most money and has the same problem as bitcoin. We showed the types of Zcash addresses and how they differ in detail in our guide to Zcash addresses: t1, z and unified.

How it will work for holders

The plan has two parts.

A fresh address and a hash-based signature. After every spend, the remaining balance moves to a new address whose key has not been revealed yet. The spend itself is authorized by a signature that cannot be forged even by someone who knows the public key. That is how one-time signatures work: one key, one signature, then a new address.

Private balance checks. An ordinary wallet asks a server how many coins sit on its addresses, and the server sees that those addresses belong to one person. Zakura has built a tool that gets the answer without showing the server which addresses the question is about. The technology is called private information retrieval (PIR). An experimental version is already available in the Vizor wallet, under the “Private queries” setting. The payments themselves remain public: the tool hides the queries, not the blockchain.

What about shielded ZEC

The new opcodes do not protect shielded payments, which hide the sender, the recipient and the amount. They need cryptography of their own, and that is separate, longer work.

They also face a threat of their own. Zcash's document on recovery after a quantum attack (ZIP-2005) warns that an attacker can already store encrypted payment records today in order to decrypt them after a future breakthrough. Coins cannot be stolen this way, but the privacy of old transfers would suffer.

Ironwood is insurance, not a full transition: it did not make the cryptography of shielded addresses quantum-resistant. Industry media report the Epoch timeline citing the project team, and those dates remain targets as well.

What ZEC holders should do now

There is no need to panic: a quantum computer capable of cracking a wallet key does not exist today. Still, a few habits are worth picking up now, and they cost nothing.

1. Do not reuse a transparent address. Once you have sent from an address, move the remaining balance to a new one. Most wallets can do this for you.
2. Do not hand out your extended public key or viewing keys. They can be used to work out other public keys of the same wallet.
3. Keep only what you spend on a transparent address. It makes more sense to shield your savings: that gives you privacy, and in the new Ironwood pool also a way to recover coins after a quantum attack.
4. Update your wallet before November 5. The NU7 upgrade is expected on mainnet that day, and coins in the old Sprout pool will become unspendable after it. Details are in our breakdown of Zcash NU7: 25-second blocks and the Sprout freeze.
5. Follow your wallet's news. When a post-quantum address type appears, migrating will be an ordinary transfer to yourself.

If you do not hold ZEC yet, the easiest way to get some is a crypto swap without registration: the coins arrive at your wallet address, and from there you decide whether to shield them or spend them.

How to buy ZEC without registration and receive it at a fresh address

VertEXchange asks for no account, email or phone number to make a swap. Create a new transparent address in your wallet, one that starts with t1, pick a pair, for example to buy Zcash with bitcoin, paste the address, and check the rate and the amount you will receive before you send anything. For ZEC, the form accepts t1 and t3 addresses and verifies their checksum, so a typo will not get through.

• The fixed rate holds for about 15 minutes, and the amount does not change while your transfer is being confirmed.
• The coins go straight to your address: VertEXchange does not hold them.
• You can add a refund address: the coins return there if the exchange does not go through.
• Personal fields of the order are deleted 24 hours after it completes, and your exchange history stays only in your browser.
• A support chat is on every page, and questions are resolved using your exchange code.

An address that has only received coins has not revealed its key yet. Once you have your ZEC, shield it in your own wallet. If you keep dollars on TRON, you can swap USDT TRC20 to ZEC, and anyone choosing between the two privacy coins may find the ZEC to Monero pair useful.

FAQ

Is Zcash quantum-resistant already?

Not yet. Support for hash-based signatures on transparent payments is slated for January 2027, and protection for the shielded part is planned for the end of 2027. Both dates are development targets.

What are hash-based signatures?

They are signatures whose security rests on hash functions rather than elliptic curves. A quantum computer that could, in theory, break today's keys would not help forge them.

Which ZEC is more at risk: transparent or shielded?

For transparent addresses that have already sent funds, the public key is visible on the blockchain, which is why the first stage protects them. Shielded coins face a different risk: payment records can be stored now and decrypted later, so it is privacy that is under threat.

Do I need to move my ZEC urgently?

No. No one has demonstrated a practical quantum attack on keys. It is enough to avoid reusing addresses and to keep your wallet updated.

How much ZEC sits on transparent addresses?

According to ZecStats data as of October 8, 2026, about 11.96 million of the 16.98 million issued, which is roughly 70%.

When will the upgrade be activated on the Zcash network?

There is no activation date. The Zakura node developers named January as the date for the code to be ready, and the decision to activate it on mainnet is made separately.