We talked to the man who claims Claude helped recover $400,000 worth of bitcoin locked in wallet for over a decade

Yesterday was “the best day of my life” for anonymous X user “Cprkrn” who said Claude helped him recover five bitcoin stuck for 11 years in a Blockchain.com wallet, encrypted with a forgotten second password. He bought five bitcoin for about “between $200 and $300,” and it’s now worth roughly $400,000.

In an X thread that has now gone viral, Cprkrn shared a post from August 8, 2023, with blockchain data showing the wallet hadn’t had any transactions since April 2015. Arkham data shows the funds were sent to a hot wallet at Hyperunit yesterday. 

“Locked out 11+ years because I got stoned and changed the password,” he posted. 

Sherwood News could not independently verify he is the owner of the wallet, as Cprkrn didn’t want to send a bitcoin transaction as proof. The timing of his posts and the transactions on the blockchain do correspond with Cprkrn’s narrative.

And while Cprkrn said, “Claude cracked this shit,” online, it’s fair to say that Claude did not “crack” the bitcoin wallet per se, but helped him find the old wallet backup file on his computer. In other words, don’t worry about Q-day level threats to cryptography yet.

“It’s exactly it. I did write down things illegibly and messed up the order of some words, so it figured that piece out, and then yeah, the seedphrase decrypted an older wallet, so yeah, it sort of went through all my files and was looking for clues with me,” Cprkrn told Sherwood, adding that he used Claude Opus 4.7 for the endeavor.

Per the Claude recap, he also posted a breakdown of what worked: “The old wallet backup was decryptable with the old second password that we already knew from a notebook mnemonic. Decrypting the old backup with the old password gave us the same private keys controlling the current funds. Swept 5BTC out.”

Total passwords tested: around 3.5 trillion.

Cprkrn, who has been in the crypto space “since college,” said he didn’t use specific prompts but rather fed Claude a ton of information.  

“There is this like bitcoin recover I tried to use on my own, and then I kind of fed that into Claude so it had password recovery to lean off of and then I talked back and forth,” he said.

He added that he had old MacBooks, old hard drives, and some cloud data repository, “so yeah, I basically gave it my full history.”

“I was taking pictures of school notebooks and sent them to Claude, trying everything to piece anything together. I also said how I make passwords. I gave Claude context,” he told Sherwood.

A few weeks ago, he said Claude said it had figured it out (but in reality, it hadn’t), so yesterday he didn’t believe it actually did it this time.  

“And then I typed in the phrase and it fitted, and I didn’t expect that tweet to go viral,” he said.

He told Sherwood that years ago, he had written down the password on an old phone he lost at a bar.

“We were playing pool, and I had my phone on a table, and then while I was shooting my shot, my buddy was trying to see if anyone had lost their phone, and some stranger took mine before I turned around/noticed,” he said. “I could be misremembering, of course, it was so long ago, but we always joked that it was his fault for accidentally giving my phone away.”

Asked whether he is now scared of wrench attacks, he said, “That was my first thing, that’s why I want to maybe cash out, it’s definitely a worry.”

So what’s next?

Cprkrn said he’s been a bitcoin proponent but has been “slightly disillusioned” by the crypto industry in recent times. When asked whether he’ll buy more bitcoin, he said, “who knows?”

“I already work in the industry, so I have exposure in other ways. I’m kind of debating sitting tight, but I’m approaching the age where a house is appealing,” he said. “I think obviously it’s a good thing for us in the long haul, but I don’t know exactly, I need to play things smart.”

Asked whether plans for his impending wedding might change, he said: “We’ll get a couple extra flowers.”