INVESTIGATIVE DOSSIER · RESEARCHED 03 OCT 2026
BITCOIN PUZZLE #43 · 43-BIT · SOLVED

Bitcoin Puzzle #43

Solved and swept on 30 Jan 2015. The private key for this 43-bit puzzle was found inside [2^42, 2^43) and the balance was moved out.

Why puzzle #43 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 #43 needs about 2^41 key tests on average.

Re-solve #43 in your browser All 256 puzzle addresses