Bitcoin user cprkrn recovered access to a wallet containing 5 Bitcoin after 11 years by leveraging Anthropic’s Claude AI to crack the lost password in May 2026 [1, 2, 3]. The recovered coins were worth approximately $400,000 USD or 2.72 million RMB at that time [1, 2, 3].
The user had lost access to the wallet after changing its password while stoned around 2015 and then forgetting it [1, 2, 3]. Early Bitcoin wallets combined hierarchical deterministic (HD) and non-HD keys, with non-HD keys stored in wallet files protected by passwords that cannot be recovered through seed phrases [1, 2]. Because of this, brute-force attempts using open-source tools like btcrecover failed to unlock the wallet for more than a decade [1, 2].
In a recent breakthrough, cprkrn found an old mnemonic seed phrase in a college notebook and uploaded their entire college computer data to Claude AI to seek a solution [1, 2, 3]. Claude AI discovered a 2019 backup wallet file on the computer and uncovered a bug in btcrecover’s password and shared key combination logic [1, 2]. After fixing this bug, Claude AI called btcrecover to test about 3.5 trillion password variations, successfully decrypting the wallet and restoring access to the private keys [1, 2].
The 5 BTC were originally purchased or stored around April 2015 [3]. After recovery, the user safely transferred the coins to a current wallet [2].
User cprkrn expressed extreme excitement, writing, "HOLY FUCKING SHIT OMG CLAUDE JUST CRACKED THIS SHIT, THANK YOU @AnthropicAI THANK YOU @DarioAmodei NAMING MY KID AFTER YOU" [1]. They also lamented being "Locked out 11+ years because I got stoned and changed the password" [3].
The key step was Claude AI’s discovery of the backup file and correction of a btcrecover bug, enabling a successful brute-force attempt through trillions of password possibilities. The recovery was completed in May 2026, ending over a decade of lost access [1, 2, 3].
