Note, 31 October 2026

Fifty signatures, one wallet: what the Binance theft says about signing

On 29 October 2026 about $2.5 billion left one Binance hot wallet in a single transaction, the largest single movement in a theft Binance puts at around $6.3 billion. Minutes earlier, a separate transaction carried fifty signed authorizations and only one applied. The signatures were valid, and how they were produced is not public.

What happened

The wallet is one a block explorer labels Binance 14, a hot wallet on Ethereum that Hypernative describes as handling customer withdrawals. One transaction emptied it, 167,464 ETH plus 63 tokens (TRM Labs), and left 1 ETH behind (Blockaid). Elliptic and CoinDesk put the sweep at about $2.5 billion. It came about three and a half minutes after the delegation was set.

Binance puts the total across its affected wallets at around $6.3 billion and says about $3 billion is frozen on chain so far (Binance on X). TRM Labs counts $6.36 billion and about $2.7 billion frozen. TRM calls it the largest hack in history.

Why fifty signatures

Since May 2025, Ethereum has let a wallet hand itself over to a program with one signed message, an authorization defined in EIP-7702. Each names the wallet's transaction counter, the nonce, and applies only if the counter equals that number exactly. Otherwise it is skipped and the transaction carries on.

That explains the fifty. A busy hot wallet sends transactions all day, each moving its counter up by one, so the sender could not know the number at landing. Signing for fifty consecutive numbers covered the range (TRM Labs, CoinDesk). Forty-nine were skipped by design and the transaction succeeded. It did not fail forty-nine times; it carried forty-nine spares.

An authorization needs a valid signature from the wallet. Binance says it found no evidence of any wallet private key leak (Binance on X).

Why it did not stop

The delegation lives on the blockchain, on the wallet's own account, not on a Binance server. Changing the keys does not remove it (Hypernative); only a new authorization signed by the wallet, pointing it at nothing, clears it (Blockaid). That happened at 00:10 UTC on 30 October (CoinDesk), nearly four hours after it was set.

Further sweeps took new deposits, the last about three and a half hours after the delegation was set (Elliptic). One of about $200 million (Blockaid) went into a wallet already frozen (TRM Labs).

Only one wallet was delegated. TRM, Hypernative and Elliptic report that every other wallet, a second one on Ethereum included, signed ordinary transfers. TRM and Hypernative count ten blockchains and Elliptic eleven, so we say about ten.

What is not known

How the signatures were produced. Binance first said the incident may involve a compromised engineer's laptop, which let an attacker reach a service container and submit unauthorized withdrawals (Binance on X), then that it had found additional points of breach and named none (CoinDesk). Its video update said the delegation "did not pass through our normal approval controls" (Elliptic). How is not public. A post-mortem is promised; this note is current to 31 October 2026.

Who did it. TRM Labs attributes the theft to North Korea, with high confidence; Binance has named no one.

Our take, and what we would build

Our take: once a signature exists, the only check left is whether it is valid, and these were. The control belongs before the signature, on the request. This is an opinion from press reports; we do not know Binance's internal set-up and do not claim it lacked any of what follows.

We would build four things: a signer that holds the key and enforces policy itself, on a separate system with its own limits, so a compromised application can ask but not decide; a ceiling on what each hot wallet holds, so one bad signature costs a bounded amount; delegation refused by policy on every hot wallet, since a payout wallet has no reason to hand itself to a program; and an alert the moment any of those wallets gains code, the on-chain mark of a delegation.

We would test it with one table: request, signed or refused, seconds to alert. A payout inside the limit is signed. A payout above the ceiling is refused. A request to delegate is refused and raises an alert within a minute.

About the film

The film is our own animation. The vault, the slips and the counter are illustration, not Binance's systems; the slips are not keys, on purpose. Binance 14 is a block explorer's label for the wallet. No address or transaction hash appears here or in the film.

Transcript

The biggest crypto theft ever used fifty signatures on one wallet. Forty-nine did nothing. One took two and a half billion dollars.

This is Binance fourteen, a hot wallet paying out all day. Every transaction moves its counter up one.

Ethereum lets a wallet hand itself to a program with one signed slip. But only at the exact number on the counter.

And the counter never stops.

So the attacker had fifty slips signed, one for each of the next fifty numbers, and sent them all at once.

Forty-nine did nothing. One matched.

Three minutes and twenty-four seconds later, one transaction emptied it. It left one ether.

Here's the part that hurts. That slip lives on the blockchain, not on Binance's servers. Only a new slip from the wallet cancels it.

So new deposits kept getting swept, for almost four hours.

That was one wallet. Elsewhere, Binance's wallets just signed transfers. Six point three billion in total. Exactly how still isn't public.

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