San FranciscoClaude found a wallet file, not cracked Bitcoin’s encryption.
A user fed their old laptop to Claude; it located a 2019 backup with a password already in a notebook, recovering 5 bitcoin worth $395,000.
Anthropic has not addressed whether the technique applies to devices the user does not own.
Sources: CoinDesk
WHAT A WALLET ACTUALLY IS
A Bitcoin wallet is not the coins — it is the private key that signs transactions spending them. Lose the key and the coins remain on the blockchain forever, visible but unspendable. Estimates suggest 3-4 million bitcoin are permanently lost this way, roughly 20% of all that will ever exist.
THE TWO LAYERS OF DEFENSE
A wallet file is itself encrypted with a user-chosen password. Recovery therefore has two distinct failure modes: lose the file, or lose the password. Cracking the password by brute force is what people imagine; finding the file (and a written-down password) is what usually works.
WHY THE ENCRYPTION HELD
Bitcoin Core encrypts wallet files with AES-256-CBC, with the key derived from the password via SHA-512 iterated tens of thousands of times. AES-256 is the same cipher the NSA approves for TOP SECRET material — no language model breaks it. The recovery here was filesystem archaeology, not cryptanalysis.
WHAT LLMs ARE GOOD AT
Searching a messy filesystem for files matching known wallet signatures, parsing old chat logs for password hints, correlating a notebook photograph with a backup timestamp — these are pattern tasks across heterogeneous data. The work a forensic analyst does in a week, an LLM with shell access does in minutes.
THE CONSENT QUESTION
The same capability — file discovery, password-hint correlation, automated decryption attempts — works identically whether the laptop is yours or stolen. US law (Computer Fraud and Abuse Act) and most jurisdictions criminalize unauthorized access regardless of the tool used. Anthropic's silence on misuse is conspicuous because the technique is trivially portable.