Tezos has launched Quantumnet, its first experimental post-quantum testnet, bringing the core components of a quantum-resistant layer-1 blockchain into a single environment for the first time. Built by engineers at Nomadic Labs, Trilitech and other ecosystem contributors, the network is described in the project’s announcement on the Tezos Spotlight blog as an early preview of a post-quantum version of Tezos, marking the first milestone toward a fully post-quantum instance of the network running on mainnet.
Why the work is starting now
No known quantum computer can yet break the elliptic-curve cryptography that blockchains rely on, but the timeline is narrowing. Quantum error correction keeps improving, resource estimates for attacking elliptic-curve cryptography have fallen considerably, and Google has set 2029 as its deadline to complete a full migration to post-quantum cryptography. Tezos co-founder Arthur Breitman said he was pleased to see the project “at the forefront of post-quantum preparedness,” framing the testnet as getting ahead of a threat rather than reacting to one.
What changes inside Quantumnet
The testnet switches on quantum-resistant replacements across several layers of the protocol. Accounts gain ML-DSA-44, the signature scheme standardized by the US National Institute of Standards and Technology, which June’s Ushuaia amendment enabled behind a feature flag. For baking rights, Quantumnet removes the Verifiable Delay Function and replaces the existing lottery with a Smooth Weighted Round Robin that distributes rights according to a baker’s weight. Consensus attestations move from BLS signatures to hash-based XMSS signatures with a post-quantum STARK aggregation system built by the LeanEthereum project, while the Data Availability Layer swaps its KZG commitments for ZODA, a two-dimensional tensor-code design that avoids materially increasing data overhead. Confidential transactions are handled at the application level by TzEL, with Sapling and timelock puzzles left out of this first iteration.
A playground before a protocol amendment
Quantumnet is explicitly experimental and not intended for production use, with hardware requirements expected to sit above the lightest Tezos setups but within the range of consumer hardware. Development will continue in the open behind a public dashboard tracking live network activity, with the aim of hardening each component and eventually submitting it as a protocol amendment proposal. The route is well-trodden: Tezos on-chain governance has already carried the network through 21 upgrades, including the 12th Lima upgrade that made the chain leaner and more secure, and the work mirrors a wider industry push that has produced proposals such as a post-quantum rewrite of Ethereum’s deposit contract.
