Tezos has launched Quantumnet, its first experimental post-quantum testnet, bringing the core components of a quantum-resistant layer-1 blockchain into one environment. Engineers at Nomadic Labs, Trilitech and other ecosystem contributors built the network, which the Tezos Spotlight blog describes as an early preview of a post-quantum version of Tezos and the first milestone toward a fully post-quantum mainnet instance. The initiative addresses a longer-term risk: no known quantum computer can currently break the elliptic-curve cryptography used by blockchains, but advances in quantum error correction and lower attack-resource estimates are narrowing the timeline. Google has set 2029 as its deadline for completing a full migration to post-quantum cryptography (cryptography designed to resist quantum attacks). Quantumnet uses ML-DSA-44 for account signatures, replaces the baking lottery with Smooth Weighted Round Robin, shifts consensus attestations to hash-based XMSS signatures with post-quantum STARK aggregation, and replaces KZG commitments in the Data Availability Layer with ZODA. TzEL handles confidential transactions at the application level, while Sapling and timelock puzzles are excluded from this iteration. The testnet is not for production use; development will continue through a public dashboard before the components may be submitted as a protocol amendment proposal.