Quantus has launched a proof-of-work mainnet designed to protect cryptocurrency transactions against future attacks from sufficiently powerful quantum computers, targeting an estimated $2.7 trillion in market value currently exposed to the long-term threat.
The network went live on Wednesday, Sept. 9, with privacy-preserving transactions, a 21 million coin supply cap and open proof-of-work mining available from launch. Its core distinction is the use of post-quantum cryptography, rather than the elliptic-curve systems used by most major blockchain networks.
Quantus uses ML-DSA, the digital-signature standard finalised by the U.S. National Institute of Standards and Technology in 2024. Transactions are authenticated with the ML-DSA-65 and ML-DSA-87 variants.
“We have known for over 30 years that if anyone builds a sufficiently large quantum computer, then elliptic curves will fail,” said Quantus co-founder and chief executive Christopher Smith.
Elliptic-curve cryptography remains central to many cryptocurrency networks. In theory, a sufficiently capable quantum computer could compromise the signature systems that protect transactions and digital assets.
Quantus estimates that about $2.7 trillion of crypto market value remains vulnerable to that future risk. NEAR and Algorand have added post-quantum transaction security, although neither has completed a transition across its entire protocol.
Rather than requiring a later migration, Quantus has built the technology into its network from the outset.
“We call upon the industry leaders to be proactive in migrating to post-quantum cryptography. Being too early is much better than being even a little too late,” Smith said.
Institutional figures including Grayscale, Fidelity Investments and Tom Lee of Bitmine have already highlighted the potential quantum threat to cryptocurrencies such as bitcoin, pointing to the lack of immediate planning. Lee has warned that bitcoin does not have agreement on how to respond to future quantum-computing risks, unlike some rival networks.
Quantus also includes two other layers. Wormhole is used for transaction privacy, while an aggregation layer is intended to increase throughput. The network is targeting 12-second blocks and says testing achieved up to 430 transactions per second.
The security model comes with a cost. A Quantus transaction using ML-DSA is approximately 7 kilobytes, compared with about 100 bytes for a standard bitcoin transaction. To manage the additional data, Quantus aggregates activity on its layer one (L1) and records succinct proofs onchain. The design is intended to become more efficient as transaction volumes grow.
Its native QTC coin is issued through proof-of-work mining, with no built-in mining advantage for Quantus Labs. Before the launch, Neodyme, Eiger, Hashcloak and V12 reviewed the network, while Immunefi organised a public audit competition.
The launch comes as AI tools become more capable of examining cryptographic systems. In July, Anthropic said Claude Mythos Preview improved the best-known attack on HAWK, a post-quantum signature candidate, after about 60 hours of work. HAWK had previously completed two rounds of expert review over two years.
Anthropic said the finding had no practical effect on production systems, but it demonstrated how AI could speed up the identification of weaknesses in cryptography. Quantus is positioning its network for a market in which quantum computing may remain a distant threat while the tools used to test security continue to advance.
