INVESTIGATIVE DOSSIER · RESEARCHED 03 OCT 2026
BITCOIN PUZZLE #19 · 19-BIT · SOLVED

Bitcoin Puzzle #19

Solved and swept on 15 Jan 2015. The private key for this 19-bit puzzle was found inside [2^18, 2^19) and the balance was moved out.

Why puzzle #19 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 #19 needs about 2^17 key tests on average, which the in-browser engine on this site finishes in seconds.

Re-solve #19 in your browser All 256 puzzle addresses