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

[ComputeNode Curtis]

Google putting a public date on its own migration carries more weight than a hundred analyst forecasts. They know better than most what Willow and its successors are actually capable of

[Starforge Daniel]

Deadlines published by big firms tend to slip, so I would treat 2029 as an intention rather than a promise. Look at how long SHA-1 lingered after everyone agreed it had to go

That said, the direction of travel matters. Once Google, the Ethereum Foundation and standards bodies all point the same way, vendors follow. Bitcoin can't opt out of the tooling around it forever

[NightCrawler]

BIP 360 gets less attention than it deserves outside developer circles. P2MR only covers short-exposure attacks, but that is a meaningful slice of the problem. Starting with something narrow that can actually ship seems smarter than waiting for a perfect all-in-one design

[Harper48]

Timing matters here, since this article is from earlier in the year and things have moved since. Worth pairing it with the Decrypt roundup on Bitcoin's three defence lanes for a fuller picture

[Kane44]

Willow at 105 qubits is nowhere near what breaking elliptic-curve keys would need. People should keep that in mind before assuming 2029 is Q-Day

The deadline is about migration, not about the attack arriving. Google just wants its systems safe well before any capable machine exists

[QuantumLeap38]

Ethereum always seems to treat these threats as engineering tasks with owners and dates. Bitcoin treats them as philosophical arguments first, and that has trade-offs both ways

[KernelKnight]

Solana's Winternitz vault approach gets undersold in these comparisons. It is opt-in, sure, but it was live in January 2025 while other chains were still writing roadmaps. Hash-based signatures are well understood and don't rely on newer lattice assumptions. The downside is usability, since fresh keys per transaction complicate wallets. Still, anyone worried can use it today

[Stu_63]

Adam Back saying no action is needed for decades has aged badly

Even if he turns out to be right about the hardware, the migration itself takes years. Waiting until the threat is obvious leaves no margin at all

[CyberRider56]

Seven years for BIP 360 is the sobering bit. Add that to 2026 and you are already past Google's deadline. Even assuming Google is being cautious, Bitcoin would be finishing its upgrade right as the risk becomes serious. I don't see how that timing works out well