The quantum computing threat to blockchain cryptography remains theoretical today, but the industry is not waiting for it to become real before acting. TRON has set the most aggressive timeline, targeting a quantum-resistant mainnet by Q3 2026. Solana has already gone further than most by deploying post-quantum digital signatures on a testnet, signaling that implementation work is actively underway rather than still in the planning phase. Ethereum is taking a longer-horizon approach, with L1 protocol upgrades projected for 2029 and full execution layer migration expected to take several additional years after that — a timeline that reflects the complexity of migrating a network with Ethereum's scale and decentralization.

Outside of individual chains, the broader crypto infrastructure layer is also mobilizing. Coinbase CEO Brian Armstrong established an independent advisory board dedicated to quantum computing and blockchain security in January 2026, and Google — whose own systems underpin much of the internet's security — has set a 2029 migration target for post-quantum cryptography. The convergence of these timelines across chains, exchanges, and major tech companies suggests the industry has collectively concluded that the window to prepare is now, even if the threat is not imminent. For investors and developers, the networks that successfully complete quantum-resistant upgrades earliest will carry a meaningful security narrative advantage — and potentially a real one — as quantum computing capabilities continue to advance through the decade.