Tezos has launched Quantumnet, an experimental blockchain network built to test post-quantum cryptography across the entire protocol, as developers prepare for the possibility that future quantum computers could undermine the cryptographic systems that secure today's blockchains.

The network was developed by teams at Nomadic Labs, Trilitech, and other contributors. Quantumnet gives validators, researchers, and developers an environment in which to evaluate an early version of Tezos that incorporates post-quantum components. The initiative does not mean the production Tezos network is currently fully resistant to quantum attacks.

With the launch, Tezos' post-quantum preparations extend beyond wallet security to validator attestations, protocol randomness, and data availability, providing a public testing environment for technology that could eventually be proposed for adoption on the mainnet.

Testing a Broader Quantum-Resistant Architecture

Tezos is an open-source, proof-of-stake blockchain that supports smart contracts and decentralized applications. Its validators, known as bakers, help secure the network and participate in protocol governance.

That governance mechanism is central to the Quantumnet approach. Developers plan to test the technology publicly, collect operational feedback, and refine the implementation before potentially submitting a protocol amendment for approval.

The work follows the Ushuaia upgrade, activated on June 30, which introduced testnet-only support for quantum-resistant user keys behind a feature flag. Those keys use ML-DSA-44, a parameter set from the ML-DSA digital-signature standard finalized by the National Institute of Standards and Technology in 2024, part of a broader standardization push that gives developers a common building block for quantum-resistant signatures. Quantumnet broadens that effort to the other cryptographic functions required to operate the blockchain.

One change involves the process used to generate the protocol's random seed. The experimental design removes the existing Verifiable Delay Function and replaces it with a weighted rotation mechanism intended to maintain fairness without relying on randomness in the same way.

The network also changes how validator attestations are combined. Developers have incorporated a post-quantum proof system derived from the LeanEthereum project to aggregate individual validator signatures — an example of post-quantum components being adapted across blockchain projects rather than built in isolation. According to the launch announcement, the system can aggregate more than 1,400 signatures per second on standard hardware. That figure applies specifically to the cryptographic aggregation operation and should not be interpreted as a measure of Quantumnet's transaction-processing capacity.

Data Availability and Private Transactions

Quantumnet also addresses the Data Availability Layer, which helps network participants access published blockchain data. Developers selected a protocol known as ZODA, which they describe as providing post-quantum protection without materially increasing communication requirements. Earlier research has also explored private post-quantum transactions through TzEL, while timelock puzzles remain a lower-priority area for future development.

Together, the changes highlight the complexity preparing a blockchain for quantum computing. Updating wallet signatures alone would leave other cryptographic dependencies vulnerable, requiring developers to evaluate the full protocol stack.

The timing of the work reflects uncertainty over when sufficiently powerful quantum computers could emerge. A widely cited concern in the field is that encrypted data captured today could be stored until quantum machines become capable of breaking the cryptography that protects it. While there is no established date for a machine capable of breaking widely used public-key cryptography, developers face long migration cycles involving software upgrades, testing, and coordination among network operators. Google has targeted 2029 for its own post-quantum cryptography migration, citing advances in quantum hardware and error correction — a preparation and migration deadline rather than a prediction that existing cryptography will fail that year.

Performance Remains a Key Challenge

Post-quantum security must also be practical for blockchain operators. Quantumnet developers have warned that the experimental network may require more powerful hardware than the current Tezos mainnet. The testing phase will therefore examine not only cryptographic security but also processing, memory, bandwidth, and storage requirements, helping developers determine whether future protections can be deployed without making network participation excessively expensive.

Quantumnet is live. Tezos' first experimental post-quantum testnet brings the core pieces of a quantum-resistant blockchain together in one place for engineers,akers and the wider technical community to test in the open. Learn more ↓

— Tezos (@tezos) September 24, 2026 (post on X)

The hardware question could be particularly important for validators operating with limited resources. A substantial increase in hardware requirements could affect the ability of smaller participants to continue running nodes. The reported signature-aggregation benchmark provides evidence about one cryptographic operation but does not establish the overall performance requirements of the network.

Tezos co-founder Arthur Breitman has welcomed the project's focus on post-quantum preparedness. Zaynah Dargaye, core Layer 1 engineering manager at Nomadic Labs, said the early testing is intended to give developers sufficient time to learn from implementation challenges, refine the technology, and establish a smoother transition.

Mainnet Transition Remains Unresolved

Quantumnet is publicly available for bakers and researchers to test, but it remains experimental and is not intended for production use. The project currently has no announced mainnet activation date or finalized migration plan for existing users.

Future work will focus on testing the cryptographic components together, measuring hardware requirements, and resolving migration issues before developers can seek approval for a protocol amendment. Signals to watch as the effort matures include operational feedback from bakers during the public testing period, published measurements of hardware requirements, and whether an amendment is ultimately put to community governance. The key objective is to establish whether post-quantum cryptography can operate efficiently across a live blockchain, providing Tezos with a practical path to upgrade its security before quantum computing poses a credible threat to existing cryptographic systems.

For the network, the initiative offers an opportunity to evaluate the technical and operational consequences of a major cryptographic transition well before any decision is made to deploy such changes on the production network.

Source: CoinTrust