Qnero: Post-Quantum Monero, Now on Testnet

Qnero is pre-alpha software on a public testnet. Testnet QNR has no value, the chain may be reset, and no independent firm has audited Qnero’s own code yet. There is no token sale.

Monero got one thing right: privacy is the default for every payment, so nobody stands out for wanting it. We think that idea deserves to survive the arrival of quantum computers. Qnero is our attempt to make sure it does.

It is live on a public testnet at qnero.io, with a browser wallet, a faucet and a block explorer. You can make a wallet and send your first private payment in about five minutes.

The problem with recorded history

Monero’s privacy rests on elliptic-curve cryptography: its ring signatures, its stealth addresses and its hidden amounts all depend on it. A large enough quantum computer breaks elliptic curves.

That matters today, because a blockchain is a permanent public record. Anyone can save Monero’s history now and wait. Once the hardware exists, that saved history can be worked backwards: amounts read, rings resolved, recipients matched to known addresses. Security people call this “harvest now, decrypt later”, and for a privacy coin it is the whole threat.

Nobody knows when that hardware arrives. What is certain is that a payment made today stays on the chain forever, so its protection has to last as long as the chain does.

What Qnero is

Qnero keeps Monero’s rules and replaces the cryptography underneath:

• Private by default. Every transfer lives in a shielded pool, with sender, recipient and amount hidden. Users get no transparent mode to leak through.
• Built from hashes and lattices. Transfers are proved with zero-knowledge proofs built only from hash functions, notes are encrypted with ML-KEM, and accounts sign with ML-DSA. The last two are the post-quantum standards NIST published in 2024.
• Mined with RandomX. The same proof-of-work algorithm Monero uses, so a CPU that mines Monero can mine Qnero with a config change. No stake, no validators, no admin keys.
• Monero’s pace. Two-minute blocks and a 21 million QNR supply cap.

If you know Monero, the mental model carries over. You still have a spend key and a view key. Key images become nullifiers. The ring grows from 16 decoys to every note ever created, because each spend proves it belongs somewhere in the whole pool.

Try it

Everything runs on the public testnet:

1. Open Qloak, the browser wallet, and create a wallet. Your keys are made and kept in the page.
2. Paste your address into the faucet and receive 10 testnet QNR.
3. Send some to a friend. Your browser proves the payment itself, which takes a little while on a laptop.
4. Look it up on silQ Road, the explorer, and see how little it can tell you.

Miners can point a stock xmrig at their own node. For now that means building the node from source; the mining guide walks through it.

Built on reviewed parts

A privacy coin is only as good as the reasons you have to trust it, so we chose to build on existing, reviewed work. Qnero is a fork of the Quantus Network chain, whose post-quantum Substrate base and zero-knowledge circuits were audited by Eiger. On top of that we wrote the shielded pool, the wallet, the explorer and the RandomX mining.

We have also run a structured internal security review of Qnero’s own code and fixed eleven of its twelve findings. The last one lands at the next testnet reset. An internal review is a first step, and an independent audit comes before anyone should trust Qnero with real value.

Honest limits

Qnero is two weeks old. Some things we know about:

• Addresses are long, around 2,500 characters, because a post-quantum encryption key is large. Copy and paste them.
• Proving a payment takes real work in the browser. It is fine on a laptop and slow on a phone.
• The long-term emission schedule, including whether there is a Monero-style tail, is still open.
• The current design sets aside 2% of the supply cap at genesis. That allocation will be held outside DigitalGuards, and the full terms will be published before any mainnet.

What comes next

This post is the short version. A technical deep dive follows, covering how a shielded transfer is proved, what exactly a node and the explorer can see, and where the post-quantum claims have limits.

Qnero is an independent DigitalGuards research project, alongside our QRL 2.0 work. Everything is open source under the MIT licence at github.com/DigitalGuards/qnero. Try the testnet, try to break it, and tell us what you find on Discord or in a GitHub issue.