Google's 2029 post-quantum deadline and why Ethereum and Solana moved before Bitcoin

[Pilgrim]

This CoinMarketCap piece is from earlier in the year, but it is worth revisiting because it keeps getting cited whenever quantum and crypto come up. Google announced a 2029 deadline to finish its own migration to post-quantum cryptography. The company said progress in quantum hardware and error correction made the threat more immediate than it had previously assumed. It was also the first time Google had published an actual timeline for rolling post-quantum protection across its products

That 2029 date is earlier than a lot of other industry estimates for Q-Day. Google specifically pointed at encryption and digital signatures as the things at risk, and framed the migration as necessary for secure authentication. The article also mentions Willow, its 105-qubit superconducting processor, as part of the backdrop. Google said it hoped a public deadline would push the rest of the industry to move faster

On the crypto side the contrast is striking. The Ethereum Foundation launched a Post-Quantum Ethereum resource hub, and its team set a 2029 target for quantum-resistant solutions at the protocol level with execution layer work following after. Vitalik Buterin said validator signatures, data storage, accounts and proofs would all need updating. Solana went a different route back in January 2025 with Winternitz vaults, which use hash-based signatures and fresh keys per transaction, though users have to opt in and it isn't a network-wide upgrade

Bitcoin is where it gets messy. Blockstream's Adam Back has argued the risk is overstated and nothing needs doing for decades. On the other side, Ethan Heilman and co-authors proposed BIP 360, which adds a Pay-to-Merkle-Root output type to protect addresses from short-exposure attacks. Heilman has said implementation could take around seven years, and the debate among developers remains unresolved

What strikes me is the mismatch between those timelines. If a company with Google's visibility into the hardware wants its own house in order by 2029, and Bitcoin's own proposal authors are talking about seven years to implement, the arithmetic is not comfortable. Ethereum has the advantage of a foundation that can set targets, while Bitcoin has deliberately avoided that kind of central coordination

I am curious whether anyone thinks Adam Back's position still holds up. It made more sense when nobody serious was publishing deadlines. Now the people building the machines are the ones saying hurry

Google Sets 2029 Quantum Deadline as Ethereum and Solana Move First | CoinMarketCapcoinmarketcap.com