For 17 years, a small mystery surrounded Bitcoin’s creation. Satoshi Nakamoto published the cryptocurrency’s original code, but nobody had managed to recreate the exact Windows program he released in 2009.
Now, a developer has reportedly cracked it with AI
The developer, known as T4T5, used Anthropic’s Claude Opus 5.5 to reconstruct the computer setup Satoshi used.
The result was remarkable. The rebuilt bitcoin.exe matched the original file’s SHA-256 hash exactly, and every byte matched.
AI Uncovers How Satoshi Built Bitcoin
The problem was surprisingly complicated.
Bitcoin’s original software was never designed to be reproducible. A different compiler, software library or even a single line ending could change the final file.
T4T5 had to reconstruct an entire development environment using software packages from 2006 to 2008.
The GitHub project now reveals details about Satoshi’s working habits.
Satoshi apparently used Windows XP with MinGW GCC 3.4.5. He compiled most of Bitcoin in debug mode but enabled maximum optimization for the hashing code used in mining.
He also upgraded part of his development toolchain midway through the project.
But the investigation uncovered something more surprising.
Is Bitcoin’s Original 2009 Software Still Missing?
The executable widely known as Bitcoin 0.1.0 was actually version 0.1.1, compiled on January 10, 2009, at 23:16 UTC.
That was two days after Bitcoin’s public announcement.
No verified copy of the January 8 launch-day executable is known to survive.
The reconstruction provides strong evidence that the preserved 2009 software matches Satoshi’s published source code, with no unexplained code hidden inside.
Its immediate security implications are limited. Still, the discovery gives Bitcoin historians something valuable: a reproducible record of how the early software was built.
And while AI is helping investigate Bitcoin’s origins, the actual launch-day program remains missing.
The search for Bitcoin’s earliest executable continues.
