Bitcoin Puzzle record
Bitcoin Puzzle #140
Where it sits on the line
- found
- open · address only
- open · public key on chain
- the line · 269
This puzzle needs about 270.5 search steps — above the line (269).
No puzzle above the line has been found yet.
Model: kangaroo. The public key has been on chain since 2019, so the square-root shortcut applies: about 2 × 2(N−1)/2 group operations.
How the work is estimatedRecord
- Known public key
- 031f6a332d3c5c4f2de2378c012f429cd109ba07d69690c6c701b6bb87860d6640
- HASH160
- ffbb35a7bb9bbe16c1aa2534f7ff11d59c8e3d1a
- Search class
- public-key
- A public key is on record, so the square-root shortcut (kangaroo) works inside the interval. A key on record is not a spend.
- Candidate interval
- 2139 → 2140 − 1
- start0x80000000000000000000000000000000000
- end0xfffffffffffffffffffffffffffffffffff
- Interval size696898287454081973172991196020261297061888 scalars. Exact BigInt bounds, not a floating estimate.
Snapshot 2 Oct 2026. The reward is the catalog's nominal allocation (N × 0.1 convention from 2023-04-16; earlier spends predate it), not a live balance. A key that matches the address proves the math, not that the coins are still there: check an explorer. Missing fields are omitted, not invented.
Mentioned in the atlas
Where #140 comes up in the room pages. rooms 12 · mentions 35
- History
-
- 2019-06-01 — Public keys revealed On-chainTimeline
- Cases
-
- Case #135 — the leak series loses another target On-chain
- What the story adds, and does not establish Self-attributionCase #135 — the leak series loses another target
- People
-
- RetiredCoder — kangaroo solves, #135 self-attributed (Self-attribution) Self-attributionThe five handles
- Myths
-
- #140 — kangaroo / BSGS Refuted
- A quantum computer can take #140 this year. Refuted
- Theories
-
- 2017 consolidation as continued control On-chainOn-chain facts
- A quantum / algorithm canary SpeculationSpeculation
+27 more mentions
- Myths
-
- A 96-bit kangaroo window is the whole of #140. Refuted
- Run kangaroo / BSGS on #71. RefutedCryptography
- Find any key whose HASH160 collides with the address. Easier than the range. RefutedCryptography
- #160 without a public key is a practical brute-force target. RefutedFalse hope / EV
- Theories
-
- The 2019 leak was a planned kangaroo experiment SpeculationSpeculation
- Reconstruct the generator (Python vs C++) SpeculationSpeculation
- FAQ
-
- Which one should I try? MethodSearch classes
- What does known public key mean? On-chainSearch classes
- Is it profitable? MethodSearch classes
- Method
-
- Known public key (#140 and like it) On-chain
- Address HASH160 versus known public key Method
- Exact ranges, as integers Method
- Kangaroo constants, named Method
- Scale
-
- #140 — width 2139 Method
- #140 Snapshot
- 2019 leak map On-chain
- What square-root does not erase Method
- Challenges
-
- If bits equals N and search bits equals N-1, what is search bits for #140? Method
- You finish a 96-bit kangaroo budget on #140. Have you searched the puzzle? Method
- Given a known compressed public key for #140, which method applies? Method
- A 96-bit window on #140. Probability the uniform random key sits inside? Method
- Start
-
- The two that matter now MethodA first sitting
- Glossary
-
- Containment MethodRange
- Library
-
- #140 briefing Method
- Two search classes MethodMethod in prose
- 2019 leak map On-chainCatalog briefings
- One-page sheetOrientation
Method
Kangaroo searches only the window you choose. Being inside the window (containment) and being found by the solver are two separate odds, and finishing a bounded run stays probabilistic.