INVESTIGATIVE DOSSIER · RESEARCHED 03 OCT 2026
BITCOIN PUZZLE #9 · 9-BIT · SOLVED

Bitcoin Puzzle #9

Solved and swept on 15 Jan 2015. The private key for this 9-bit puzzle was found inside [2^8, 2^9) and the balance was moved out.

Why puzzle #9 still matters

A solved puzzle is a benchmark. Running a cracker against it should recover the real private key, which is how you tell genuine code from a toy. Puzzle #9 needs about 2^7 key tests on average, which the in-browser engine on this site finishes in seconds.

Re-solve #9 in your browser All 256 puzzle addresses