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Proof: Vietnamese professor cracks 55-year-old math puzzle, inspired by juggling

The record — the exact bytes that were hashed

{"first_seen":"2026-10-02T23:02:36Z","headline":"Vietnamese professor cracks 55-year-old math puzzle, inspired by juggling","kind":"front-page-headline","rank":1,"source":"vnexpress","url":"https://e.vnexpress.net/news/news/education/vietnamese-professor-cracks-55-year-old-math-puzzle-inspired-by-juggling-5127532.html","v":1}

Download headline-fbd3341fa59f.json

SHA-256

fbd3341fa59f6cba9196c73e15f916131af598c191bc752fc70476337a39edd5

OpenTimestamps

Confirmed in Bitcoin block 969645, mined 2026-10-02 23:16 UTC.

Download headline-fbd3341fa59f.json.ots

Wayback Machine

• The record pageCaptured 2026-10-03 00:00 UTC — view the capture.
• The story pageCaptured 2026-10-02 23:07 UTC — view the capture.

Check it yourself — none of this needs this site

1. Hash the record: sha256sum headline-fbd3341fa59f.json prints fbd3341fa59f6cba9196c73e15f916131af598c191bc752fc70476337a39edd5. Its first twelve characters are the end of this record's address.
2. Drop headline-fbd3341fa59f.json and headline-fbd3341fa59f.json.ots onto opentimestamps.org, which checks the receipt against the Bitcoin block chain. Or, with the OpenTimestamps client and a Bitcoin node: ots verify headline-fbd3341fa59f.json.ots (ots upgrade first while the receipt is pending).
3. Open the Wayback Machine's captures above: the capture of the record page shows this hash as it stood then, and the capture of the story page shows the newsroom's own page.

Sealed automatically, 4 min after it was first seen.