INVESTIGATIVE DOSSIER · RESEARCHED 03 OCT 2026
BITCOIN PUZZLE #38 · 38-BIT · SOLVED

Bitcoin Puzzle #38

Solved and swept on 19 Jan 2015. The private key for this 38-bit puzzle was found inside [2^37, 2^38) and the balance was moved out.

Why puzzle #38 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 #38 needs about 2^36 key tests on average.

Re-solve #38 in your browser All 256 puzzle addresses