Key takeaways
- Ethereum Foundation researcher Justin Drake says AI could break ECDSA wallet signatures in a worst case of months, not years.
- Bunker mode means moving funds to fresh addresses whose public keys have never appeared onchain, starting with large holders.
- Vitalik Buterin agrees the risk is real but warns botched migrations can cost more than hacks.
An Ethereum Foundation researcher is telling bitcoin and ether holders to prepare for "bunker mode," a defensive plan built around one fear: that artificial intelligence could find a way to break wallet cryptography long before quantum computers do. Justin Drake raised the alarm on X this week, and Ethereum co-founder Vitalik Buterin agreed the risk is real while warning people not to panic. No one has shown a working attack. But the warning has started a serious conversation about how crypto holders protect their coins.
What Justin Drake said
According to The Block, Drake called on the blockchain industry to plan for bunker mode on October 7, describing it as his personal recommendation and not a claim that existing cryptography has already been broken. His concern is ECDSA, the signature scheme Bitcoin and Ethereum use to approve transactions.
The usual worry about ECDSA is "q-day," the point when quantum computers become strong enough to crack today's public key cryptography. Drake's argument is different. He thinks advances in AI could lead to a classical shortcut, one that runs on ordinary hardware. The Block reports he said such a break could let an attacker recover a private key in about a week using something like a large cluster of GPUs. In the worst case, he said, this could arrive in "months not years."
CoinDesk reports that Drake pointed to patterns in the elliptic curve math behind these signatures, patterns that a strong enough AI might learn to exploit. Hash functions, by contrast, are designed to leave as little pattern as possible.
Why now
Drake cited recent AI progress in mathematics. Both outlets mention that OpenAI published 722 mathematical manuscripts produced by an internal model. CoinDesk adds that some results have computer checkable proofs while others are unverified and could contain errors. The Block quotes Drake saying that "mathematical superintelligence is upon us."
CoinDesk also lists a string of security incidents this year where AI played a role, including a volunteer Bitcoin Red Team that used AI models to scan 390 Bitcoin software projects in about 27 hours and logged nearly 5,000 possible flaws, 85 of them rated critical. The same report says Coinkite suspected AI helped an attacker find a five year old firmware bug used to drain Coldcard hardware wallets of at least 1,367 BTC starting July 30.
What bunker mode means for crypto wallets
Neither outlet gives a formal definition. From Drake's recommendations, bunker mode is a defensive posture: keep public keys hidden, move funds carefully and wait for stronger cryptography. He told The Block that safely leaving bunker mode would require "post-AI cryptography."
To understand why hiding a public key matters, it helps to know how crypto wallets work. A wallet has a private key, the secret that signs payments, and a public key the network uses to check those signatures. Getting the private key from the public key is supposed to take an impossible amount of computing. An attacker needs the public key as a starting point.
Here is the catch. On many bitcoin addresses, the public key stays hidden behind a hash until the owner spends from that address. Once you send a transaction, the key is visible onchain for good. On Ethereum, CoinDesk notes, any account that has ever sent a transaction has exposed its public key. That includes accounts holding stablecoins and tokenized funds, which run on the same signature system.
The numbers behind the risk
CoinDesk reported this week that more than 6 million bitcoin sit behind exposed public keys. The Block says Project Eleven's Bitcoin Risq List, a tracker of addresses with exposed keys, covers more than 14 million addresses. About 20,000 exposed addresses linked to Satoshi Nakamoto each hold 50 BTC. Drake called these "Satoshi's shield," arguing that an attacker would likely go after those large, old addresses first, which could give smaller wallets some breathing room.
Drake's recommendations
According to The Block, Drake suggested:
- Moving most funds to fresh addresses that have never signed a transaction, so the public key remains hidden behind a hash
- Starting with large and sophisticated holders
- After an address signs a transaction, moving any leftover balance to a new address
- Doing all of this in a controlled way, without rushing
- Urging Binance, Bitbank, Robinhood, Bitfinex and Tether to consider stronger protection for their cold storage
- Favoring hash based cryptography and formal verification over the long term
Vitalik Buterin urges caution
Buterin agreed that the risk is real and backed reducing public key exposure where it is practical, according to CoinDesk. But he warned holders not to rush, because moving coins carries its own danger. "I personally have lost more money in botched migrations than I have lost in all hacks combined," he wrote, as quoted by CoinDesk.
He also raised a broader concern. CoinDesk reports Buterin believes AI could weaken some quantum resistant cryptography too, including lattice based schemes behind a signature standard approved by the US National Institute of Standards and Technology. He wrote there is a good chance lattice security takes serious hits from AI driven math within two years. Ethereum's long term roadmap increasingly favors hash based signatures, which he sees as having fewer openings for surprise shortcuts. If you want background on the network itself, see our explainer on what Ethereum is and how it works.
Who is affected
The people with the most exposure are long term holders who reuse one address, exchanges and custodians with large cold wallets, and anyone holding assets on Ethereum accounts that have sent transactions. CoinDesk also reported that bunker mode is a far greater challenge for institutions than for individuals, since custody firms manage huge numbers of addresses and complex signing setups.
For a typical person holding a small amount of bitcoin, the immediate risk is low. Current Ethereum guidance, cited by The Block, still says quantum computers cannot break the network's cryptography today and users do not need to act. Drake's warning is about a possible future break, not a known one.
What you can do now
Nothing here calls for panic selling or rushed transfers. Sensible steps for regular holders include:
- Stop reusing addresses. Most modern bitcoin wallets generate a new receiving address each time.
- If you hold a large balance on an address that has already sent funds, consider moving it to a fresh address in your own wallet, slowly and with a small test transaction first.
- Keep firmware and wallet software updated, since AI is also helping attackers find ordinary software bugs.
- Be wary of anyone who contacts you offering to "secure" or "migrate" your coins. Scammers jump on news like this. Our guide on how to spot a crypto scam covers the warning signs.
If you are newer to this, our plain English guide to what bitcoin is explains addresses and keys in more detail.
What to watch next
The Ethereum Foundation targets December 2029 for moving the network to quantum resistant cryptography, according to CoinDesk. Drake's worst case would arrive well before that. Watch for whether major exchanges respond to his cold storage call, whether Bitcoin developers speed up work on new signature schemes, and whether any researcher demonstrates real progress against elliptic curve keys. Follow our crypto coverage for updates.
Frequently asked questions
What is bunker mode in crypto?
Bunker mode is Justin Drake's term for a defensive plan where holders move funds to addresses whose public keys have never appeared onchain, while the industry prepares stronger cryptography in case AI finds a way to break wallet signatures.
Has AI broken bitcoin or Ethereum encryption?
No. CoinDesk found no demonstrated practical attack on bitcoin or Ethereum wallet keys. Drake's warning is about a possible future risk.
Should I move my bitcoin right now?
Not in a rush. Buterin warned that botched migrations can cause losses. If you hold a large balance on an address that has already sent transactions, a careful move to a fresh address is a reasonable step.
Which addresses are most exposed?
Addresses that have sent transactions, reused addresses and old addresses with visible public keys. On Ethereum, any account that has sent a transaction has an exposed public key.
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